pm24.git/kernel/power, branch rust-fixes-6.6

PM: hibernate: Fix the exclusive get block device in test_resume mode

2023-09-12T09:45:15Z

Commit 5904de0d735b ("PM: hibernate: Do not get block device exclusively in test_resume mode") fixes a hibernation issue under test_resume mode. That commit is supposed to open the block device in non-exclusive mode when in test_resume. However the code does the opposite, which is against its description. In summary, the swap device is only opened exclusively by swsusp_check() with its corresponding *close(), and must be in non test_resume mode. This is to avoid the race condition that different processes scribble the device at the same time. All the other cases should use non-exclusive mode. Fix it by really disabling exclusive mode under test_resume. Fixes: 5904de0d735b ("PM: hibernate: Do not get block device exclusively in test_resume mode") Closes: https://lore.kernel.org/lkml/000000000000761f5f0603324129@google.com/ Reported-by: Pengfei Xu Signed-off-by: Chen Yu Tested-by: Chenzhou Feng Signed-off-by: Rafael J. Wysocki

PM: hibernate: Rename function parameter from snapshot_test to exclusive

2023-09-12T09:45:15Z

Several functions reply on snapshot_test to decide whether to open the resume device exclusively. However there is no strict connection between the snapshot_test and the open mode. Rename the 'snapshot_test' input parameter to 'exclusive' to better reflect the use case. No functional change is expected. Signed-off-by: Chen Yu Signed-off-by: Rafael J. Wysocki

Merge tag 'tty-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2023-09-01T16:38:00Z

Pull tty/serial driver updates from Greg KH: "Here is the big set of tty and serial driver changes for 6.6-rc1. Lots of cleanups in here this cycle, and some driver updates. Short summary is: - Jiri's continued work to make the tty code and apis be a bit more sane with regards to modern kernel coding style and types - cpm_uart driver updates - n_gsm updates and fixes - meson driver updates - sc16is7xx driver updates - 8250 driver updates for different hardware types - qcom-geni driver fixes - tegra serial driver change - stm32 driver updates - synclink_gt driver cleanups - tty structure size reduction All of these have been in linux-next this week with no reported issues. The last bit of cleanups from Jiri and the tty structure size reduction came in last week, a bit late but as they were just style changes and size reductions, I figured they should get into this merge cycle so that others can work on top of them with no merge conflicts" * tag 'tty-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (199 commits) tty: shrink the size of struct tty_struct by 40 bytes tty: n_tty: deduplicate copy code in n_tty_receive_buf_real_raw() tty: n_tty: extract ECHO_OP processing to a separate function tty: n_tty: unify counts to size_t tty: n_tty: use u8 for chars and flags tty: n_tty: simplify chars_in_buffer() tty: n_tty: remove unsigned char casts from character constants tty: n_tty: move newline handling to a separate function tty: n_tty: move canon handling to a separate function tty: n_tty: use MASK() for masking out size bits tty: n_tty: make n_tty_data::num_overrun unsigned tty: n_tty: use time_is_before_jiffies() in n_tty_receive_overrun() tty: n_tty: use 'num' for writes' counts tty: n_tty: use output character directly tty: n_tty: make flow of n_tty_receive_buf_common() a bool Revert "tty: serial: meson: Add a earlycon for the T7 SoC" Documentation: devices.txt: Fix minors for ttyCPM* Documentation: devices.txt: Remove ttySIOC* Documentation: devices.txt: Remove ttyIOC* serial: 8250_bcm7271: improve bcm7271 8250 port ...

Merge branches 'pm-sleep', 'pm-qos' and 'powercap'

2023-08-25T19:23:30Z

Merge system-wide power management changes and power capping updates for 6.6-rc1: - Add device PM helpers to allow a device to remain powered-on during system-wide transitions (Ulf Hansson). - Rework hibernation memory snapshotting to avoid storing pages filled with zeros in hibernation image files (Brian Geffon). - Add check to make sure that CPU latency QoS constraints do not use negative values (Clive Lin). - Optimize rp->domains memory allocation in the Intel RAPL power capping driver (xiongxin). - Remove recursion while parsing zones in the arm_scmi power capping driver (Cristian Marussi). * pm-sleep: PM: sleep: Add helpers to allow a device to remain powered-on PM: hibernate: don't store zero pages in the image file * pm-qos: PM: QoS: Add check to make sure CPU latency is non-negative * powercap: powercap: intel_rapl: Optimize rp->domains memory allocation powercap: arm_scmi: Remove recursion while parsing zones

PM: QoS: Add check to make sure CPU latency is non-negative

2023-08-22T19:37:29Z

CPU latency should never be negative, which will be incorrectly high when converted to unsigned data type. Commit 8d36694245f2 ("PM: QoS: Add check to make sure CPU freq is non-negative") makes sure CPU frequency is non-negative to fix incorrect behavior in freqency QoS. Add an analogous check to make sure CPU latency is non-negative so as to prevent this problem from happening in CPU latency QoS. Signed-off-by: Clive Lin [ rjw: Changelog edits ] Signed-off-by: Rafael J. Wysocki

Merge commit b320441c04c9 ("Merge tag 'tty-6.5-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty") into tty-next

2023-08-20T12:29:37Z

We need the serial-core fixes in here as well. Signed-off-by: Greg Kroah-Hartman

Merge back system-wide sleep material for v6.6.

2023-08-14T07:55:44Z

PM: hibernate: fix resume_store() return value when hibernation not available

2023-08-07T09:41:11Z

On a laptop with hibernation set up but not actively used, and with secure boot and lockdown enabled kernel, 6.5-rc1 gets stuck on boot with the following repeated messages: A start job is running for Resume from hibernation using device /dev/system/swap (24s / no limit) lockdown_is_locked_down: 25311154 callbacks suppressed Lockdown: systemd-hiberna: hibernation is restricted; see man kernel_lockdown.7 ... Checking the resume code leads to commit cc89c63e2fe3 ("PM: hibernate: move finding the resume device out of software_resume") which inadvertently changed the return value from resume_store() to 0 when !hibernation_available(). This apparently translates to userspace write() returning 0 as in number of bytes written, and userspace looping indefinitely in the attempt to write the intended value. Fix this by returning the full number of bytes that were to be written, as that's what was done before the commit. Fixes: cc89c63e2fe3 ("PM: hibernate: move finding the resume device out of software_resume") Signed-off-by: Vlastimil Babka Reviewed-by: Christoph Hellwig Acked-by: Greg Kroah-Hartman Signed-off-by: Rafael J. Wysocki

tty: sysrq: switch sysrq handlers from int to u8

2023-07-25T17:21:03Z

The passed parameter to sysrq handlers is a key (a character). So change the type from 'int' to 'u8'. Let it specifically be 'u8' for two reasons: * unsigned: unsigned values come from the upper layers (devices) and the tty layer assumes unsigned on most places, and * 8-bit: as that what's supposed to be one day in all the layers built on the top of tty. (Currently, we use mostly 'unsigned char' and somewhere still only 'char'. (But that also translates to the former thanks to -funsigned-char.)) Signed-off-by: Jiri Slaby (SUSE) Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Cc: Huacai Chen Cc: WANG Xuerui Cc: Thomas Bogendoerfer Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Christophe Leroy Cc: "David S. Miller" Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Thomas Zimmermann Cc: David Airlie Cc: Daniel Vetter Cc: Jason Wessel Cc: Daniel Thompson Cc: Douglas Anderson Cc: "Rafael J. Wysocki" Cc: Len Brown Cc: Pavel Machek Cc: "Paul E. McKenney" Cc: Frederic Weisbecker Cc: Neeraj Upadhyay Cc: Joel Fernandes Cc: Josh Triplett Cc: Boqun Feng Cc: Steven Rostedt Cc: Mathieu Desnoyers Cc: Lai Jiangshan Cc: Zqiang Acked-by: Thomas Zimmermann # DRM Acked-by: WANG Xuerui # loongarch Acked-by: Paul E. McKenney Acked-by: Daniel Thompson Link: https://lore.kernel.org/r/20230712081811.29004-3-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

PM: hibernate: don't store zero pages in the image file

2023-07-24T07:51:59Z

On ChromeOS we've observed a considerable number of in-use pages filled with zeros. Today with hibernate it's entirely possible that saveable pages are just zero filled. Since we're already copying pages word-by-word in do_copy_page it becomes almost free to determine if a page was completely filled with zeros. This change introduces a new bitmap which will track these zero pages. If a page is zero it will not be included in the saved image, instead to track these zero pages in the image file we will introduce a new flag which we will set on the packed PFN list. When reading back in the image file we will detect these zero page PFNs and rebuild the zero page bitmap. When the image is being loaded through calls to write_next_page if we encounter a zero page we will silently memset it to 0 and then continue on to the next page. Given the implementation in snapshot_read_next/snapshot_write_next this change will be transparent to non-compressed/compressed and swsusp modes of operation. To provide some concrete numbers from simple ad-hoc testing, on a device which was lightly in use we saw that: PM: hibernation: Image created (964408 pages copied, 548304 zero pages) Of the approximately 6.2GB of saveable pages 2.2GB (36%) were just zero filled and could be tracked entirely within the packed PFN list. The savings would obviously be much lower for lzo compressed images, but even in the case of compression not copying pages across to the compression threads will still speed things up. It's also possible that we would see better overall compression ratios as larger regions of "real data" would improve the compressibility. Finally, such an approach could dramatically improve swsusp performance as each one of those zero pages requires a write syscall to reload, by handling it as part of the packed PFN list we're able to fully avoid that. Signed-off-by: Brian Geffon [ rjw: Whitespace adjustments, removal of redundant parentheses ] Signed-off-by: Rafael J. Wysocki