From 62d85b3bf9d978ed4b6b2aeef5cf0ccf1423906e Mon Sep 17 00:00:00 2001
From: Ivan Mironov <mironov.ivan@gmail.com>
Date: Tue, 8 Jan 2019 12:23:52 +0500
Subject: drm/fb-helper: Partially bring back workaround for bugs of SDL 1.2

SDL 1.2 sets all fields related to the pixel format to zero in some
cases[1]. Prior to commit db05c48197759 ("drm: fb-helper: Reject all
pixel format changing requests"), there was an unintentional workaround
for this that existed for more than a decade. First in device-specific DRM
drivers, then here in drm_fb_helper.c.

Previous code containing this workaround just ignores pixel format fields
from userspace code. Not a good thing either, as this way, driver may
silently use pixel format different from what client actually requested,
and this in turn will lead to displaying garbage on the screen. I think
that returning EINVAL to userspace in this particular case is the right
option, so I decided to left code from problematic commit untouched
instead of just reverting it entirely.

Here is the steps required to reproduce this problem exactly:
	1) Compile fceux[2] with SDL 1.2.15 and without GTK or OpenGL
	   support. SDL should be compiled with fbdev support (which is
	   on by default).
	2) Create /etc/fb.modes with following contents (values seems
	   not used, and just required to trigger problematic code in
	   SDL):

		mode "test"
		    geometry 1 1 1 1 1
		    timings 1 1 1 1 1 1 1
		endmode

	3) Create ~/.fceux/fceux.cfg with following contents:

		SDL.Hotkeys.Quit = 27
		SDL.DoubleBuffering = 1

	4) Ensure that screen resolution is at least 1280x960 (e.g.
	   append "video=Virtual-1:1280x960-32" to the kernel cmdline
	   for qemu/QXL).

	5) Try to run fceux on VT with some ROM file[3]:

		# ./fceux color_test.nes

[1] SDL 1.2.15 source code, src/video/fbcon/SDL_fbvideo.c,
    FB_SetVideoMode()
[2] http://www.fceux.com
[3] Example ROM: https://github.com/bokuweb/rustynes/blob/master/roms/color_test.nes

Reported-by: saahriktu <mail@saahriktu.org>
Suggested-by: saahriktu <mail@saahriktu.org>
Cc: stable@vger.kernel.org
Fixes: db05c48197759 ("drm: fb-helper: Reject all pixel format changing requests")
Signed-off-by: Ivan Mironov <mironov.ivan@gmail.com>
[danvet: Delete misleading comment.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190108072353.28078-2-mironov.ivan@gmail.com
Link: https://patchwork.freedesktop.org/patch/msgid/20190108072353.28078-2-mironov.ivan@gmail.com
---
 drivers/gpu/drm/drm_fb_helper.c | 126 +++++++++++++++++++++++-----------------
 1 file changed, 73 insertions(+), 53 deletions(-)

(limited to 'drivers/gpu/drm/drm_fb_helper.c')

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index d3af098b0922..2d7ce9d3143f 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1621,6 +1621,64 @@ static bool drm_fb_pixel_format_equal(const struct fb_var_screeninfo *var_1,
 	       var_1->transp.msb_right == var_2->transp.msb_right;
 }
 
+static void drm_fb_helper_fill_pixel_fmt(struct fb_var_screeninfo *var,
+					 u8 depth)
+{
+	switch (depth) {
+	case 8:
+		var->red.offset = 0;
+		var->green.offset = 0;
+		var->blue.offset = 0;
+		var->red.length = 8; /* 8bit DAC */
+		var->green.length = 8;
+		var->blue.length = 8;
+		var->transp.offset = 0;
+		var->transp.length = 0;
+		break;
+	case 15:
+		var->red.offset = 10;
+		var->green.offset = 5;
+		var->blue.offset = 0;
+		var->red.length = 5;
+		var->green.length = 5;
+		var->blue.length = 5;
+		var->transp.offset = 15;
+		var->transp.length = 1;
+		break;
+	case 16:
+		var->red.offset = 11;
+		var->green.offset = 5;
+		var->blue.offset = 0;
+		var->red.length = 5;
+		var->green.length = 6;
+		var->blue.length = 5;
+		var->transp.offset = 0;
+		break;
+	case 24:
+		var->red.offset = 16;
+		var->green.offset = 8;
+		var->blue.offset = 0;
+		var->red.length = 8;
+		var->green.length = 8;
+		var->blue.length = 8;
+		var->transp.offset = 0;
+		var->transp.length = 0;
+		break;
+	case 32:
+		var->red.offset = 16;
+		var->green.offset = 8;
+		var->blue.offset = 0;
+		var->red.length = 8;
+		var->green.length = 8;
+		var->blue.length = 8;
+		var->transp.offset = 24;
+		var->transp.length = 8;
+		break;
+	default:
+		break;
+	}
+}
+
 /**
  * drm_fb_helper_check_var - implementation for &fb_ops.fb_check_var
  * @var: screeninfo to check
@@ -1654,6 +1712,20 @@ int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
 		return -EINVAL;
 	}
 
+	/*
+	 * Workaround for SDL 1.2, which is known to be setting all pixel format
+	 * fields values to zero in some cases. We treat this situation as a
+	 * kind of "use some reasonable autodetected values".
+	 */
+	if (!var->red.offset     && !var->green.offset    &&
+	    !var->blue.offset    && !var->transp.offset   &&
+	    !var->red.length     && !var->green.length    &&
+	    !var->blue.length    && !var->transp.length   &&
+	    !var->red.msb_right  && !var->green.msb_right &&
+	    !var->blue.msb_right && !var->transp.msb_right) {
+		drm_fb_helper_fill_pixel_fmt(var, fb->format->depth);
+	}
+
 	/*
 	 * drm fbdev emulation doesn't support changing the pixel format at all,
 	 * so reject all pixel format changing requests.
@@ -1967,59 +2039,7 @@ void drm_fb_helper_fill_var(struct fb_info *info, struct drm_fb_helper *fb_helpe
 	info->var.yoffset = 0;
 	info->var.activate = FB_ACTIVATE_NOW;
 
-	switch (fb->format->depth) {
-	case 8:
-		info->var.red.offset = 0;
-		info->var.green.offset = 0;
-		info->var.blue.offset = 0;
-		info->var.red.length = 8; /* 8bit DAC */
-		info->var.green.length = 8;
-		info->var.blue.length = 8;
-		info->var.transp.offset = 0;
-		info->var.transp.length = 0;
-		break;
-	case 15:
-		info->var.red.offset = 10;
-		info->var.green.offset = 5;
-		info->var.blue.offset = 0;
-		info->var.red.length = 5;
-		info->var.green.length = 5;
-		info->var.blue.length = 5;
-		info->var.transp.offset = 15;
-		info->var.transp.length = 1;
-		break;
-	case 16:
-		info->var.red.offset = 11;
-		info->var.green.offset = 5;
-		info->var.blue.offset = 0;
-		info->var.red.length = 5;
-		info->var.green.length = 6;
-		info->var.blue.length = 5;
-		info->var.transp.offset = 0;
-		break;
-	case 24:
-		info->var.red.offset = 16;
-		info->var.green.offset = 8;
-		info->var.blue.offset = 0;
-		info->var.red.length = 8;
-		info->var.green.length = 8;
-		info->var.blue.length = 8;
-		info->var.transp.offset = 0;
-		info->var.transp.length = 0;
-		break;
-	case 32:
-		info->var.red.offset = 16;
-		info->var.green.offset = 8;
-		info->var.blue.offset = 0;
-		info->var.red.length = 8;
-		info->var.green.length = 8;
-		info->var.blue.length = 8;
-		info->var.transp.offset = 24;
-		info->var.transp.length = 8;
-		break;
-	default:
-		break;
-	}
+	drm_fb_helper_fill_pixel_fmt(&info->var, fb->format->depth);
 
 	info->var.xres = fb_width;
 	info->var.yres = fb_height;
-- 
cgit v1.2.3-70-g09d2


From 66a8d5bfb518f9f12d47e1d2dce1732279f9451e Mon Sep 17 00:00:00 2001
From: Ivan Mironov <mironov.ivan@gmail.com>
Date: Tue, 8 Jan 2019 12:23:53 +0500
Subject: drm/fb-helper: Ignore the value of fb_var_screeninfo.pixclock

Strict requirement of pixclock to be zero breaks support of SDL 1.2
which contains hardcoded table of supported video modes with non-zero
pixclock values[1].

To better understand which pixclock values are considered valid and how
driver should handle these values, I briefly examined few existing fbdev
drivers and documentation in Documentation/fb/. And it looks like there
are no strict rules on that and actual behaviour varies:

	* some drivers treat (pixclock == 0) as "use defaults" (uvesafb.c);
	* some treat (pixclock == 0) as invalid value which leads to
	  -EINVAL (clps711x-fb.c);
	* some pass converted pixclock value to hardware (uvesafb.c);
	* some are trying to find nearest value from predefined table
          (vga16fb.c, video_gx.c).

Given this, I believe that it should be safe to just ignore this value if
changing is not supported. It seems that any portable fbdev application
which was not written only for one specific device working under one
specific kernel version should not rely on any particular behaviour of
pixclock anyway.

However, while enabling SDL1 applications to work out of the box when
there is no /etc/fb.modes with valid settings, this change affects the
video mode choosing logic in SDL. Depending on current screen
resolution, contents of /etc/fb.modes and resolution requested by
application, this may lead to user-visible difference (not always):
image will be displayed in a right way, but it will be aligned to the
left instead of center. There is no "right behaviour" here as well, as
emulated fbdev, opposing to old fbdev drivers, simply ignores any
requsts of video mode changes with resolutions smaller than current.

The easiest way to reproduce this problem is to install sdl-sopwith[2],
remove /etc/fb.modes file if it exists, and then try to run sopwith
from console without X. At least in Fedora 29, sopwith may be simply
installed from standard repositories.

[1] SDL 1.2.15 source code, src/video/fbcon/SDL_fbvideo.c, vesa_timings
[2] http://sdl-sopwith.sourceforge.net/

Signed-off-by: Ivan Mironov <mironov.ivan@gmail.com>
Cc: stable@vger.kernel.org
Fixes: 79e539453b34e ("DRM: i915: add mode setting support")
Fixes: 771fe6b912fca ("drm/radeon: introduce kernel modesetting for radeon hardware")
Fixes: 785b93ef8c309 ("drm/kms: move driver specific fb common code to helper functions (v2)")
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190108072353.28078-3-mironov.ivan@gmail.com
---
 drivers/gpu/drm/drm_fb_helper.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

(limited to 'drivers/gpu/drm/drm_fb_helper.c')

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 2d7ce9d3143f..d73703a695e8 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1690,9 +1690,14 @@ int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
 	struct drm_fb_helper *fb_helper = info->par;
 	struct drm_framebuffer *fb = fb_helper->fb;
 
-	if (var->pixclock != 0 || in_dbg_master())
+	if (in_dbg_master())
 		return -EINVAL;
 
+	if (var->pixclock != 0) {
+		DRM_DEBUG("fbdev emulation doesn't support changing the pixel clock, value of pixclock is ignored\n");
+		var->pixclock = 0;
+	}
+
 	if ((drm_format_info_block_width(fb->format, 0) > 1) ||
 	    (drm_format_info_block_height(fb->format, 0) > 1))
 		return -EINVAL;
-- 
cgit v1.2.3-70-g09d2


From 78de14c23e031420aa5f61973583635eccd6cd2a Mon Sep 17 00:00:00 2001
From: Noralf Trønnes <noralf@tronnes.org>
Date: Fri, 25 Jan 2019 16:03:00 +0100
Subject: drm/fb-helper: generic: Fix drm_fbdev_client_restore()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

If fbdev setup has failed, lastclose will give a NULL pointer deref:

[   77.794295] [drm:drm_lastclose]
[   77.794414] [drm:drm_lastclose] driver lastclose completed
[   77.794660] Unable to handle kernel NULL pointer dereference at virtual address 00000014
[   77.809460] pgd = b376b71b
[   77.818275] [00000014] *pgd=175ba831, *pte=00000000, *ppte=00000000
[   77.830813] Internal error: Oops: 17 [#1] ARM
[   77.840963] Modules linked in: mi0283qt mipi_dbi tinydrm raspberrypi_hwmon gpio_backlight backlight snd_bcm2835(C) bcm2835_rng rng_core
[   77.865203] CPU: 0 PID: 527 Comm: lt-modetest Tainted: G         C        5.0.0-rc1+ #1
[   77.879525] Hardware name: BCM2835
[   77.889185] PC is at restore_fbdev_mode+0x20/0x164
[   77.900261] LR is at drm_fb_helper_restore_fbdev_mode_unlocked+0x54/0x9c
[   78.002446] Process lt-modetest (pid: 527, stack limit = 0x7a3d5c14)
[   78.291030] Backtrace:
[   78.300815] [<c04f2d0c>] (restore_fbdev_mode) from [<c04f4708>] (drm_fb_helper_restore_fbdev_mode_unlocked+0x54/0x9c)
[   78.319095]  r9:d8a8a288 r8:d891acf0 r7:d7697910 r6:00000000 r5:d891ac00 r4:d891ac00
[   78.334432] [<c04f46b4>] (drm_fb_helper_restore_fbdev_mode_unlocked) from [<c04f47e8>] (drm_fbdev_client_restore+0x18/0x20)
[   78.353296]  r8:d76978c0 r7:d7697910 r6:d7697950 r5:d7697800 r4:d891ac00 r3:c04f47d0
[   78.368689] [<c04f47d0>] (drm_fbdev_client_restore) from [<c051b6b4>] (drm_client_dev_restore+0x7c/0xc0)
[   78.385982] [<c051b638>] (drm_client_dev_restore) from [<c04f8fd0>] (drm_lastclose+0xc4/0xd4)
[   78.402332]  r8:d76978c0 r7:d7471080 r6:c0e0c088 r5:d8a85e00 r4:d7697800
[   78.416688] [<c04f8f0c>] (drm_lastclose) from [<c04f9088>] (drm_release+0xa8/0x10c)
[   78.431929]  r5:d8a85e00 r4:d7697800
[   78.442989] [<c04f8fe0>] (drm_release) from [<c02640c4>] (__fput+0x104/0x1c8)
[   78.457740]  r8:d5ccea10 r7:d96cfb10 r6:00000008 r5:d74c1b90 r4:d8a8a280
[   78.472043] [<c0263fc0>] (__fput) from [<c02641ec>] (____fput+0x18/0x1c)
[   78.486363]  r10:00000006 r9:d7722000 r8:c01011c4 r7:00000000 r6:c0ebac6c r5:d892a340
[   78.501869]  r4:d8a8a280
[   78.512002] [<c02641d4>] (____fput) from [<c013ef1c>] (task_work_run+0x98/0xac)
[   78.527186] [<c013ee84>] (task_work_run) from [<c010cc54>] (do_work_pending+0x4f8/0x570)
[   78.543238]  r7:d7722030 r6:00000004 r5:d7723fb0 r4:00000000
[   78.556825] [<c010c75c>] (do_work_pending) from [<c0101034>] (slow_work_pending+0xc/0x20)
[   78.674256] ---[ end trace 70d3a60cf739be3b ]---

Fix by using drm_fb_helper_lastclose() which checks if fbdev is in use.

Fixes: 9060d7f49376 ("drm/fb-helper: Finish the generic fbdev emulation")
Cc: stable@vger.kernel.org
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190125150300.33268-1-noralf@tronnes.org
---
 drivers/gpu/drm/drm_fb_helper.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

(limited to 'drivers/gpu/drm/drm_fb_helper.c')

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 31fcf94bf825..c5c79986f9c5 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -3185,9 +3185,7 @@ static void drm_fbdev_client_unregister(struct drm_client_dev *client)
 
 static int drm_fbdev_client_restore(struct drm_client_dev *client)
 {
-	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
-
-	drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper);
+	drm_fb_helper_lastclose(client->dev);
 
 	return 0;
 }
-- 
cgit v1.2.3-70-g09d2


From 1e55a53a28d3e52a68e11917dd25a216c3e7c182 Mon Sep 17 00:00:00 2001
From: Matt Roper <matthew.d.roper@intel.com>
Date: Fri, 1 Feb 2019 17:23:26 -0800
Subject: drm: Trivial comment grammar cleanups

Most of these are just cases where code comments used contractions
(it's, who's) where they actually mean to use a possessive pronoun (its,
whose) or vice-versa.

Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190202012326.20096-1-matthew.d.roper@intel.com
---
 drivers/gpu/drm/drm_agpsupport.c         |  2 +-
 drivers/gpu/drm/drm_atomic_helper.c      |  8 ++++----
 drivers/gpu/drm/drm_atomic_uapi.c        |  4 ++--
 drivers/gpu/drm/drm_bufs.c               |  4 ++--
 drivers/gpu/drm/drm_connector.c          |  2 +-
 drivers/gpu/drm/drm_dp_mst_topology.c    | 30 +++++++++++++++---------------
 drivers/gpu/drm/drm_fb_helper.c          |  2 +-
 drivers/gpu/drm/drm_file.c               |  2 +-
 drivers/gpu/drm/drm_framebuffer.c        |  2 +-
 drivers/gpu/drm/drm_gem.c                |  2 +-
 drivers/gpu/drm/drm_mm.c                 |  2 +-
 drivers/gpu/drm/drm_modes.c              |  2 +-
 drivers/gpu/drm/drm_property.c           |  2 +-
 drivers/gpu/drm/drm_vblank.c             |  2 +-
 include/drm/drm_atomic.h                 |  2 +-
 include/drm/drm_client.h                 |  2 +-
 include/drm/drm_connector.h              |  2 +-
 include/drm/drm_mode_config.h            |  2 +-
 include/drm/drm_modeset_helper_vtables.h |  2 +-
 include/drm/drm_modeset_lock.h           |  2 +-
 include/drm/ttm/ttm_bo_driver.h          |  2 +-
 21 files changed, 40 insertions(+), 40 deletions(-)

(limited to 'drivers/gpu/drm/drm_fb_helper.c')

diff --git a/drivers/gpu/drm/drm_agpsupport.c b/drivers/gpu/drm/drm_agpsupport.c
index 737f02885c28..40fba1c04dfc 100644
--- a/drivers/gpu/drm/drm_agpsupport.c
+++ b/drivers/gpu/drm/drm_agpsupport.c
@@ -348,7 +348,7 @@ int drm_agp_bind_ioctl(struct drm_device *dev, void *data,
  * \return zero on success or a negative number on failure.
  *
  * Verifies the AGP device is present and has been acquired and looks up the
- * AGP memory entry. If the memory it's currently bound, unbind it via
+ * AGP memory entry. If the memory is currently bound, unbind it via
  * unbind_agp(). Frees it via free_agp() as well as the entry itself
  * and unlinks from the doubly linked list it's inserted in.
  */
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 6fe2303fccd9..440cfa91162a 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -330,7 +330,7 @@ update_connector_routing(struct drm_atomic_state *state,
 	 * Since the connector can be unregistered at any point during an
 	 * atomic check or commit, this is racy. But that's OK: all we care
 	 * about is ensuring that userspace can't do anything but shut off the
-	 * display on a connector that was destroyed after its been notified,
+	 * display on a connector that was destroyed after it's been notified,
 	 * not before.
 	 */
 	if (drm_connector_is_unregistered(connector) && crtc_state->active) {
@@ -685,7 +685,7 @@ drm_atomic_helper_check_modeset(struct drm_device *dev,
 
 	/*
 	 * After all the routing has been prepared we need to add in any
-	 * connector which is itself unchanged, but who's crtc changes it's
+	 * connector which is itself unchanged, but whose crtc changes its
 	 * configuration. This must be done before calling mode_fixup in case a
 	 * crtc only changed its mode but has the same set of connectors.
 	 */
@@ -1670,7 +1670,7 @@ EXPORT_SYMBOL(drm_atomic_helper_async_commit);
  * drm_atomic_helper_setup_commit() and related functions.
  *
  * Committing the actual hardware state is done through the
- * &drm_mode_config_helper_funcs.atomic_commit_tail callback, or it's default
+ * &drm_mode_config_helper_funcs.atomic_commit_tail callback, or its default
  * implementation drm_atomic_helper_commit_tail().
  *
  * RETURNS:
@@ -1893,7 +1893,7 @@ crtc_or_fake_commit(struct drm_atomic_state *state, struct drm_crtc *crtc)
  * functions. drm_atomic_helper_wait_for_dependencies() must be called before
  * actually committing the hardware state, and for nonblocking commits this call
  * must be placed in the async worker. See also drm_atomic_helper_swap_state()
- * and it's stall parameter, for when a driver's commit hooks look at the
+ * and its stall parameter, for when a driver's commit hooks look at the
  * &drm_crtc.state, &drm_plane.state or &drm_connector.state pointer directly.
  *
  * Completion of the hardware commit step must be signalled using
diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
index c40889888a16..defc03a9cd1c 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -44,8 +44,8 @@
  * DOC: overview
  *
  * This file contains the marshalling and demarshalling glue for the atomic UAPI
- * in all it's form: The monster ATOMIC IOCTL itself, code for GET_PROPERTY and
- * SET_PROPERTY IOCTls. Plus interface functions for compatibility helpers and
+ * in all its forms: The monster ATOMIC IOCTL itself, code for GET_PROPERTY and
+ * SET_PROPERTY IOCTLs. Plus interface functions for compatibility helpers and
  * drivers which have special needs to construct their own atomic updates, e.g.
  * for load detect or similiar.
  */
diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c
index a39ab2193bfe..e407adb033e7 100644
--- a/drivers/gpu/drm/drm_bufs.c
+++ b/drivers/gpu/drm/drm_bufs.c
@@ -494,7 +494,7 @@ int drm_legacy_getmap_ioctl(struct drm_device *dev, void *data,
  * isn't in use.
  *
  * Searches the map on drm_device::maplist, removes it from the list, see if
- * its being used, and free any associate resource (such as MTRR's) if it's not
+ * it's being used, and free any associated resource (such as MTRR's) if it's not
  * being on use.
  *
  * \sa drm_legacy_addmap
@@ -621,7 +621,7 @@ int drm_legacy_rmmap_ioctl(struct drm_device *dev, void *data,
 		}
 	}
 
-	/* List has wrapped around to the head pointer, or its empty we didn't
+	/* List has wrapped around to the head pointer, or it's empty we didn't
 	 * find anything.
 	 */
 	if (list_empty(&dev->maplist) || !map) {
diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index e3ff73695c32..dd40eff0911c 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -1066,7 +1066,7 @@ EXPORT_SYMBOL(drm_mode_create_dvi_i_properties);
  *
  * content type (HDMI specific):
  *	Indicates content type setting to be used in HDMI infoframes to indicate
- *	content type for the external device, so that it adjusts it's display
+ *	content type for the external device, so that it adjusts its display
  *	settings accordingly.
  *
  *	The value of this property can be one of the following:
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index b1c63e9cdf8a..6d0d8e01f16e 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -941,7 +941,7 @@ static void drm_dp_free_mst_branch_device(struct kref *kref)
  * in-memory topology state from being changed in the middle of critical
  * operations like changing the internal state of payload allocations. This
  * means each branch and port will be considered to be connected to the rest
- * of the topology until it's topology refcount reaches zero. Additionally,
+ * of the topology until its topology refcount reaches zero. Additionally,
  * for ports this means that their associated &struct drm_connector will stay
  * registered with userspace until the port's refcount reaches 0.
  *
@@ -979,8 +979,8 @@ static void drm_dp_free_mst_branch_device(struct kref *kref)
  *    same way as the C pointers used to reference a structure.
  *
  * As you can see in the above figure, every branch increments the topology
- * refcount of it's children, and increments the malloc refcount of it's
- * parent. Additionally, every payload increments the malloc refcount of it's
+ * refcount of its children, and increments the malloc refcount of its
+ * parent. Additionally, every payload increments the malloc refcount of its
  * assigned port by 1.
  *
  * So, what would happen if MSTB #3 from the above figure was unplugged from
@@ -997,9 +997,9 @@ static void drm_dp_free_mst_branch_device(struct kref *kref)
  * of its parent, and finally its own malloc refcount. For MSTB #4 and port
  * #4, this means they both have been disconnected from the topology and freed
  * from memory. But, because payload #2 is still holding a reference to port
- * #3, port #3 is removed from the topology but it's &struct drm_dp_mst_port
+ * #3, port #3 is removed from the topology but its &struct drm_dp_mst_port
  * is still accessible from memory. This also means port #3 has not yet
- * decremented the malloc refcount of MSTB #3, so it's &struct
+ * decremented the malloc refcount of MSTB #3, so its &struct
  * drm_dp_mst_branch will also stay allocated in memory until port #3's
  * malloc refcount reaches 0.
  *
@@ -1139,7 +1139,7 @@ static void drm_dp_destroy_mst_branch_device(struct kref *kref)
 
 /**
  * drm_dp_mst_topology_try_get_mstb() - Increment the topology refcount of a
- * branch device unless its zero
+ * branch device unless it's zero
  * @mstb: &struct drm_dp_mst_branch to increment the topology refcount of
  *
  * Attempts to grab a topology reference to @mstb, if it hasn't yet been
@@ -1265,7 +1265,7 @@ static void drm_dp_destroy_port(struct kref *kref)
 
 /**
  * drm_dp_mst_topology_try_get_port() - Increment the topology refcount of a
- * port unless its zero
+ * port unless it's zero
  * @port: &struct drm_dp_mst_port to increment the topology refcount of
  *
  * Attempts to grab a topology reference to @port, if it hasn't yet been
@@ -1471,7 +1471,7 @@ static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
 			port->mstb->port_parent = port;
 			/*
 			 * Make sure this port's memory allocation stays
-			 * around until it's child MSTB releases it
+			 * around until its child MSTB releases it
 			 */
 			drm_dp_mst_get_port_malloc(port);
 
@@ -2271,7 +2271,7 @@ static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
 					struct drm_dp_payload *payload)
 {
 	DRM_DEBUG_KMS("\n");
-	/* its okay for these to fail */
+	/* it's okay for these to fail */
 	if (port) {
 		drm_dp_payload_send_msg(mgr, port, id, 0);
 	}
@@ -2947,7 +2947,7 @@ enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector
 {
 	enum drm_connector_status status = connector_status_disconnected;
 
-	/* we need to search for the port in the mgr in case its gone */
+	/* we need to search for the port in the mgr in case it's gone */
 	port = drm_dp_mst_topology_get_port_validated(mgr, port);
 	if (!port)
 		return connector_status_disconnected;
@@ -3013,7 +3013,7 @@ struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_
 {
 	struct edid *edid = NULL;
 
-	/* we need to search for the port in the mgr in case its gone */
+	/* we need to search for the port in the mgr in case it's gone */
 	port = drm_dp_mst_topology_get_port_validated(mgr, port);
 	if (!port)
 		return NULL;
@@ -3180,7 +3180,7 @@ EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots);
  * Releases any VCPI slots that have been allocated to a port in the atomic
  * state. Any atomic drivers which support MST must call this function in
  * their &drm_connector_helper_funcs.atomic_check() callback when the
- * connector will no longer have VCPI allocated (e.g. because it's CRTC was
+ * connector will no longer have VCPI allocated (e.g. because its CRTC was
  * removed) when it had VCPI allocated in the previous atomic state.
  *
  * It is OK to call this even if @port has been removed from the system.
@@ -3268,7 +3268,7 @@ bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
 	DRM_DEBUG_KMS("initing vcpi for pbn=%d slots=%d\n",
 		      pbn, port->vcpi.num_slots);
 
-	/* Keep port allocated until it's payload has been removed */
+	/* Keep port allocated until its payload has been removed */
 	drm_dp_mst_get_port_malloc(port);
 	drm_dp_mst_topology_put_port(port);
 	return true;
@@ -3300,7 +3300,7 @@ EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
 {
 	/*
-	 * A port with VCPI will remain allocated until it's VCPI is
+	 * A port with VCPI will remain allocated until its VCPI is
 	 * released, no verified ref needed
 	 */
 
@@ -3317,7 +3317,7 @@ void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
 				struct drm_dp_mst_port *port)
 {
 	/*
-	 * A port with VCPI will remain allocated until it's VCPI is
+	 * A port with VCPI will remain allocated until its VCPI is
 	 * released, no verified ref needed
 	 */
 
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index c5c79986f9c5..523b1067f1ed 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -2483,7 +2483,7 @@ static int drm_pick_crtcs(struct drm_fb_helper *fb_helper,
 /*
  * This function checks if rotation is necessary because of panel orientation
  * and if it is, if it is supported.
- * If rotation is necessary and supported, its gets set in fb_crtc.rotation.
+ * If rotation is necessary and supported, it gets set in fb_crtc.rotation.
  * If rotation is necessary but not supported, a DRM_MODE_ROTATE_* flag gets
  * or-ed into fb_helper->sw_rotations. In drm_setup_crtcs_fb() we check if only
  * one bit is set and then we set fb_info.fbcon_rotate_hint to make fbcon do
diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
index 46f48f245eb5..b1838a41ad43 100644
--- a/drivers/gpu/drm/drm_file.c
+++ b/drivers/gpu/drm/drm_file.c
@@ -701,7 +701,7 @@ int drm_event_reserve_init(struct drm_device *dev,
 EXPORT_SYMBOL(drm_event_reserve_init);
 
 /**
- * drm_event_cancel_free - free a DRM event and release it's space
+ * drm_event_cancel_free - free a DRM event and release its space
  * @dev: DRM device
  * @p: tracking structure for the pending event
  *
diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
index 7abcb265a108..d8d75e25f6fb 100644
--- a/drivers/gpu/drm/drm_framebuffer.c
+++ b/drivers/gpu/drm/drm_framebuffer.c
@@ -773,7 +773,7 @@ EXPORT_SYMBOL(drm_framebuffer_lookup);
  * @fb: fb to unregister
  *
  * Drivers need to call this when cleaning up driver-private framebuffers, e.g.
- * those used for fbdev. Note that the caller must hold a reference of it's own,
+ * those used for fbdev. Note that the caller must hold a reference of its own,
  * i.e. the object may not be destroyed through this call (since it'll lead to a
  * locking inversion).
  *
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 2896ff60552f..d0b9f6a9953f 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -660,7 +660,7 @@ void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
 EXPORT_SYMBOL(drm_gem_put_pages);
 
 /**
- * drm_gem_object_lookup - look up a GEM object from it's handle
+ * drm_gem_object_lookup - look up a GEM object from its handle
  * @filp: DRM file private date
  * @handle: userspace handle
  *
diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c
index 3cc5fbd78ee2..2b4f373736c7 100644
--- a/drivers/gpu/drm/drm_mm.c
+++ b/drivers/gpu/drm/drm_mm.c
@@ -816,7 +816,7 @@ EXPORT_SYMBOL(drm_mm_scan_add_block);
  * When the scan list is empty, the selected memory nodes can be freed. An
  * immediately following drm_mm_insert_node_in_range_generic() or one of the
  * simpler versions of that function with !DRM_MM_SEARCH_BEST will then return
- * the just freed block (because its at the top of the free_stack list).
+ * the just freed block (because it's at the top of the free_stack list).
  *
  * Returns:
  * True if this block should be evicted, false otherwise. Will always
diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index adce9a26bac9..a28e7a91c8be 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -1272,7 +1272,7 @@ const char *drm_get_mode_status_name(enum drm_mode_status status)
  * @verbose: be verbose about it
  *
  * This helper function can be used to prune a display mode list after
- * validation has been completed. All modes who's status is not MODE_OK will be
+ * validation has been completed. All modes whose status is not MODE_OK will be
  * removed from the list, and if @verbose the status code and mode name is also
  * printed to dmesg.
  */
diff --git a/drivers/gpu/drm/drm_property.c b/drivers/gpu/drm/drm_property.c
index 79c77c3cad86..f8ec8f9c3e7a 100644
--- a/drivers/gpu/drm/drm_property.c
+++ b/drivers/gpu/drm/drm_property.c
@@ -866,7 +866,7 @@ err:
  * value doesn't become invalid part way through the property update due to
  * race).  The value returned by reference via 'obj' should be passed back
  * to drm_property_change_valid_put() after the property is set (and the
- * object to which the property is attached has a chance to take it's own
+ * object to which the property is attached has a chance to take its own
  * reference).
  */
 bool drm_property_change_valid_get(struct drm_property *property,
diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
index cde71ee95a8f..a1b65d26d761 100644
--- a/drivers/gpu/drm/drm_vblank.c
+++ b/drivers/gpu/drm/drm_vblank.c
@@ -48,7 +48,7 @@
  * Drivers must initialize the vertical blanking handling core with a call to
  * drm_vblank_init(). Minimally, a driver needs to implement
  * &drm_crtc_funcs.enable_vblank and &drm_crtc_funcs.disable_vblank plus call
- * drm_crtc_handle_vblank() in it's vblank interrupt handler for working vblank
+ * drm_crtc_handle_vblank() in its vblank interrupt handler for working vblank
  * support.
  *
  * Vertical blanking interrupts can be enabled by the DRM core or by drivers
diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
index 811b4a92568f..3b97b2bfaad9 100644
--- a/include/drm/drm_atomic.h
+++ b/include/drm/drm_atomic.h
@@ -192,7 +192,7 @@ struct drm_private_state;
  * private objects. The structure itself is used as a vtable to identify the
  * associated private object type. Each private object type that needs to be
  * added to the atomic states is expected to have an implementation of these
- * hooks and pass a pointer to it's drm_private_state_funcs struct to
+ * hooks and pass a pointer to its drm_private_state_funcs struct to
  * drm_atomic_get_private_obj_state().
  */
 struct drm_private_state_funcs {
diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h
index 971bb7853776..8b552b1a6ce9 100644
--- a/include/drm/drm_client.h
+++ b/include/drm/drm_client.h
@@ -26,7 +26,7 @@ struct drm_client_funcs {
 	 * @unregister:
 	 *
 	 * Called when &drm_device is unregistered. The client should respond by
-	 * releasing it's resources using drm_client_release().
+	 * releasing its resources using drm_client_release().
 	 *
 	 * This callback is optional.
 	 */
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 994161374a49..8fe22abb1e10 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -912,7 +912,7 @@ struct drm_connector {
 	/**
 	 * @ycbcr_420_allowed : This bool indicates if this connector is
 	 * capable of handling YCBCR 420 output. While parsing the EDID
-	 * blocks, its very helpful to know, if the source is capable of
+	 * blocks it's very helpful to know if the source is capable of
 	 * handling YCBCR 420 outputs.
 	 */
 	bool ycbcr_420_allowed;
diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
index 1e6cb885994d..7f60e8eb269a 100644
--- a/include/drm/drm_mode_config.h
+++ b/include/drm/drm_mode_config.h
@@ -361,7 +361,7 @@ struct drm_mode_config {
 	 *
 	 * This is the big scary modeset BKL which protects everything that
 	 * isn't protect otherwise. Scope is unclear and fuzzy, try to remove
-	 * anything from under it's protection and move it into more well-scoped
+	 * anything from under its protection and move it into more well-scoped
 	 * locks.
 	 *
 	 * The one important thing this protects is the use of @acquire_ctx.
diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h
index 61142aa0ab23..cfb7be40bed7 100644
--- a/include/drm/drm_modeset_helper_vtables.h
+++ b/include/drm/drm_modeset_helper_vtables.h
@@ -1013,7 +1013,7 @@ struct drm_plane_helper_funcs {
 	 * @prepare_fb:
 	 *
 	 * This hook is to prepare a framebuffer for scanout by e.g. pinning
-	 * it's backing storage or relocating it into a contiguous block of
+	 * its backing storage or relocating it into a contiguous block of
 	 * VRAM. Other possible preparatory work includes flushing caches.
 	 *
 	 * This function must not block for outstanding rendering, since it is
diff --git a/include/drm/drm_modeset_lock.h b/include/drm/drm_modeset_lock.h
index a308f2d6496f..7b8841065b11 100644
--- a/include/drm/drm_modeset_lock.h
+++ b/include/drm/drm_modeset_lock.h
@@ -68,7 +68,7 @@ struct drm_modeset_acquire_ctx {
 /**
  * struct drm_modeset_lock - used for locking modeset resources.
  * @mutex: resource locking
- * @head: used to hold it's place on &drm_atomi_state.locked list when
+ * @head: used to hold its place on &drm_atomi_state.locked list when
  *    part of an atomic update
  *
  * Used for locking CRTCs and other modeset resources.
diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h
index 1021106438b2..56642fbb6f73 100644
--- a/include/drm/ttm/ttm_bo_driver.h
+++ b/include/drm/ttm/ttm_bo_driver.h
@@ -867,7 +867,7 @@ int ttm_bo_pipeline_move(struct ttm_buffer_object *bo,
  *
  * @bo: A pointer to a struct ttm_buffer_object.
  *
- * Pipelined gutting a BO of it's backing store.
+ * Pipelined gutting a BO of its backing store.
  */
 int ttm_bo_pipeline_gutting(struct ttm_buffer_object *bo);
 
-- 
cgit v1.2.3-70-g09d2