| Message ID | 20240821092121.16447-1-chenyufan@vivo.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v1] ImgTec powerVR DRM driver: Convert to use time_before macro | expand |
Hi Chen, Thanks for the patch! Just a couple minor notes. On 21/08/2024 10:21, Chen Yufan wrote: > Subject: [PATCH v1] ImgTec powerVR DRM driver: Convert to use time_before macro The prefix here should be based on the source path. For us, that's "drm/imagination:". > Use time_before instead of direct subtraction for readability. I think the real justification here is correctness. The code as it currently exists is susceptible to overflow issues that are handled correctly by the time_*() macros. > Signed-off-by: Chen Yufan <chenyufan@vivo.com> Please add a Fixes: tag as per [1]. > --- > drivers/gpu/drm/imagination/pvr_ccb.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/imagination/pvr_ccb.c b/drivers/gpu/drm/imagination/pvr_ccb.c > index 4deeac7ed..b7d5f9ca3 100644 > --- a/drivers/gpu/drm/imagination/pvr_ccb.c > +++ b/drivers/gpu/drm/imagination/pvr_ccb.c > @@ -321,7 +321,7 @@ static int pvr_kccb_reserve_slot_sync(struct pvr_device *pvr_dev) > bool reserved = false; > u32 retries = 0; > > - while ((jiffies - start_timestamp) < (u32)RESERVE_SLOT_TIMEOUT || > + while (time_before(jiffies, start_timestamp + (u32)RESERVE_SLOT_TIMEOUT) || You might as well drop the cast here too; it only seems to have existed here as an attempt to correclty deal with overflow. Cheers, Matt [1]: https://www.kernel.org/doc/html/latest/process/submitting-patches.html#describe-your-changes > retries < RESERVE_SLOT_MIN_RETRIES) { > reserved = pvr_kccb_try_reserve_slot(pvr_dev); > if (reserved)
diff --git a/drivers/gpu/drm/imagination/pvr_ccb.c b/drivers/gpu/drm/imagination/pvr_ccb.c index 4deeac7ed..b7d5f9ca3 100644 --- a/drivers/gpu/drm/imagination/pvr_ccb.c +++ b/drivers/gpu/drm/imagination/pvr_ccb.c @@ -321,7 +321,7 @@ static int pvr_kccb_reserve_slot_sync(struct pvr_device *pvr_dev) bool reserved = false; u32 retries = 0; - while ((jiffies - start_timestamp) < (u32)RESERVE_SLOT_TIMEOUT || + while (time_before(jiffies, start_timestamp + (u32)RESERVE_SLOT_TIMEOUT) || retries < RESERVE_SLOT_MIN_RETRIES) { reserved = pvr_kccb_try_reserve_slot(pvr_dev); if (reserved)
Use time_before instead of direct subtraction for readability. Signed-off-by: Chen Yufan <chenyufan@vivo.com> --- drivers/gpu/drm/imagination/pvr_ccb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)