diff options
| author | Chunfeng Yun <chunfeng.yun@mediatek.com> | 2022-08-19 16:05:55 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-08-19 10:39:05 +0200 |
| commit | 8b13ea05117ffad4727b0971ed09122d5c91c4dc (patch) | |
| tree | b70e974be3fcd4123130f0ef8d4263c031d9b07f /drivers/usb | |
| parent | c1e5c2f0cb8a22ec2e14af92afc7006491bebabb (diff) | |
usb: xhci-mtk: relax TT periodic bandwidth allocation
Currently uses the worst case byte budgets on FS/LS bus bandwidth,
for example, for an isochronos IN endpoint with 192 bytes budget, it
will consume the whole 5 uframes(188 * 5) while the actual FS bus
budget should be just 192 bytes. It cause that many usb audio headsets
with 3 interfaces (audio input, audio output, and HID) cannot be
configured.
To improve it, changes to use "approximate" best case budget for FS/LS
bandwidth management. For the same endpoint from the above example,
the approximate best case budget is now reduced to (188 * 2) bytes.
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20220819080556.32215-1-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/host/xhci-mtk-sch.c | 11 |
1 files changed, 2 insertions, 9 deletions
diff --git a/drivers/usb/host/xhci-mtk-sch.c b/drivers/usb/host/xhci-mtk-sch.c index 06a6b19acaae..a17bc584ee99 100644 --- a/drivers/usb/host/xhci-mtk-sch.c +++ b/drivers/usb/host/xhci-mtk-sch.c @@ -425,7 +425,6 @@ static int check_fs_bus_bw(struct mu3h_sch_ep_info *sch_ep, int offset) static int check_sch_tt(struct mu3h_sch_ep_info *sch_ep, u32 offset) { - u32 extra_cs_count; u32 start_ss, last_ss; u32 start_cs, last_cs; @@ -461,18 +460,12 @@ static int check_sch_tt(struct mu3h_sch_ep_info *sch_ep, u32 offset) if (last_cs > 7) return -ESCH_CS_OVERFLOW; - if (sch_ep->ep_type == ISOC_IN_EP) - extra_cs_count = (last_cs == 7) ? 1 : 2; - else /* ep_type : INTR IN / INTR OUT */ - extra_cs_count = 1; - - cs_count += extra_cs_count; if (cs_count > 7) cs_count = 7; /* HW limit */ sch_ep->cs_count = cs_count; - /* one for ss, the other for idle */ - sch_ep->num_budget_microframes = cs_count + 2; + /* ss, idle are ignored */ + sch_ep->num_budget_microframes = cs_count; /* * if interval=1, maxp >752, num_budge_micoframe is larger |