| Message ID | 20240502210252.11617-2-wsa+renesas@sang-engineering.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/1] drm: arm: display: komeda: komeda_crtc: use 'time_left' variable with wait_for_completion_timeout() | expand |
On Thu, May 02, 2024 at 11:02:53PM +0200, Wolfram Sang wrote: > There is a confusing pattern in the kernel to use a variable named 'timeout' to > store the result of wait_for_completion_timeout() causing patterns like: > > timeout = wait_for_completion_timeout(...) > if (!timeout) return -ETIMEDOUT; > > with all kinds of permutations. Use 'time_left' as a variable to make the code > self explaining. > > Fix to the proper variable type 'unsigned long' while here. > > Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> > --- > drivers/gpu/drm/arm/display/komeda/komeda_crtc.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c > index 2c661f28410e..c867acb737d6 100644 > --- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c > +++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c > @@ -294,7 +294,7 @@ komeda_crtc_flush_and_wait_for_flip_done(struct komeda_crtc *kcrtc, > struct komeda_dev *mdev = kcrtc->master->mdev; > struct completion *flip_done; > struct completion temp; > - int timeout; > + unsigned long time_left; > > /* if caller doesn't send a flip_done, use a private flip_done */ > if (input_flip_done) { > @@ -308,8 +308,8 @@ komeda_crtc_flush_and_wait_for_flip_done(struct komeda_crtc *kcrtc, > mdev->funcs->flush(mdev, kcrtc->master->id, 0); > > /* wait the flip take affect.*/ > - timeout = wait_for_completion_timeout(flip_done, HZ); > - if (timeout == 0) { > + time_left = wait_for_completion_timeout(flip_done, HZ); > + if (time_left == 0) { Honestly, if the name of the variable is confusing I would get rid of it completely. Can you send a patch that removes the timeout variable and here just does: if (wait_for_completion_timeout(flip_done, HZ) == 0) { Thanks, Liviu > DRM_ERROR("wait pipe%d flip done timeout\n", kcrtc->master->id); > if (!input_flip_done) { > unsigned long flags; > -- > 2.43.0 >
> > /* wait the flip take affect.*/ > > - timeout = wait_for_completion_timeout(flip_done, HZ); > > - if (timeout == 0) { > > + time_left = wait_for_completion_timeout(flip_done, HZ); > > + if (time_left == 0) { > > Honestly, if the name of the variable is confusing I would get rid of it completely. Can you > send a patch that removes the timeout variable and here just does: > > if (wait_for_completion_timeout(flip_done, HZ) == 0) { Can do. I think, though, that using 'time_left' is still easier to understand. However, this code block is simple enough and it is your driver, so I'll send v2 later.
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c index 2c661f28410e..c867acb737d6 100644 --- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c +++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c @@ -294,7 +294,7 @@ komeda_crtc_flush_and_wait_for_flip_done(struct komeda_crtc *kcrtc, struct komeda_dev *mdev = kcrtc->master->mdev; struct completion *flip_done; struct completion temp; - int timeout; + unsigned long time_left; /* if caller doesn't send a flip_done, use a private flip_done */ if (input_flip_done) { @@ -308,8 +308,8 @@ komeda_crtc_flush_and_wait_for_flip_done(struct komeda_crtc *kcrtc, mdev->funcs->flush(mdev, kcrtc->master->id, 0); /* wait the flip take affect.*/ - timeout = wait_for_completion_timeout(flip_done, HZ); - if (timeout == 0) { + time_left = wait_for_completion_timeout(flip_done, HZ); + if (time_left == 0) { DRM_ERROR("wait pipe%d flip done timeout\n", kcrtc->master->id); if (!input_flip_done) { unsigned long flags;
There is a confusing pattern in the kernel to use a variable named 'timeout' to store the result of wait_for_completion_timeout() causing patterns like: timeout = wait_for_completion_timeout(...) if (!timeout) return -ETIMEDOUT; with all kinds of permutations. Use 'time_left' as a variable to make the code self explaining. Fix to the proper variable type 'unsigned long' while here. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> --- drivers/gpu/drm/arm/display/komeda/komeda_crtc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)