[PATCH 3/5] drm/msm: Remove call to reservation_object_test_signaled_rcu before wait

2016-08-12 Thread Sumit Semwal 
Hi Chris,

On 11 August 2016 at 20:16, Chris Wilson  wrote:
> Since fence_wait_timeout_reservation_object_wait_timeout_rcu() with a
> timeout of 0 becomes reservation_object_test_signaled_rcu(), we do not
> need to handle such conversion in the caller. The only challenge are
> those callers that wish to differentiate the error code between the
> nonblocking busy check and potentially blocking wait.
>
> Signed-off-by: Chris Wilson 
> Cc: Rob Clark 
> ---
>  drivers/gpu/drm/msm/msm_gem.c | 22 ++
>  1 file changed, 10 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
> index 6cd4af443139..ab07eb6de25e 100644
> --- a/drivers/gpu/drm/msm/msm_gem.c
> +++ b/drivers/gpu/drm/msm/msm_gem.c
> @@ -584,18 +584,16 @@ int msm_gem_cpu_prep(struct drm_gem_object *obj, 
> uint32_t op, ktime_t *timeout)
>  {
> struct msm_gem_object *msm_obj = to_msm_bo(obj);
> bool write = !!(op & MSM_PREP_WRITE);
> -
> -   if (op & MSM_PREP_NOSYNC) {
> -   if (!reservation_object_test_signaled_rcu(msm_obj->resv, 
> write))
> -   return -EBUSY;
> -   } else {
> -   int ret;
> -
> -   ret = reservation_object_wait_timeout_rcu(msm_obj->resv, 
> write,
> -   true, timeout_to_jiffies(timeout));
> -   if (ret <= 0)
> -   return ret == 0 ? -ETIMEDOUT : ret;
> -   }
> +   unsigned long remain =
> +   op & MSG_PREP_NOSYNC ? 0 : timeout_to_jiffies(timeout);
> +   long ret;
> +
> +   ret = reservation_object_wait_timeout_rcu(msm_obj->resv, write,
> + true,  remain);
> +   if (ret == 0)
> +   return remain == 9 ? -EBUSY : -ETIMEDOUT;

Am sure this must be a typo - 0 instead of 9?

> +   else if (ret < 0)
> +   return ret;
>
> /* TODO cache maintenance */
>
> --
> 2.8.1
>
> ___
> dri-devel mailing list
> dri-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

[PATCH 3/5] drm/msm: Remove call to reservation_object_test_signaled_rcu before wait

2016-08-11 Thread Chris Wilson 
On Thu, Aug 11, 2016 at 11:19:50PM +0530, Sumit Semwal wrote:
> Hi Chris,
> 
> On 11 August 2016 at 20:16, Chris Wilson  wrote:
> > Since fence_wait_timeout_reservation_object_wait_timeout_rcu() with a
> > timeout of 0 becomes reservation_object_test_signaled_rcu(), we do not
> > need to handle such conversion in the caller. The only challenge are
> > those callers that wish to differentiate the error code between the
> > nonblocking busy check and potentially blocking wait.
> >
> > Signed-off-by: Chris Wilson 
> > Cc: Rob Clark 
> > ---
> >  drivers/gpu/drm/msm/msm_gem.c | 22 ++
> >  1 file changed, 10 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
> > index 6cd4af443139..ab07eb6de25e 100644
> > --- a/drivers/gpu/drm/msm/msm_gem.c
> > +++ b/drivers/gpu/drm/msm/msm_gem.c
> > @@ -584,18 +584,16 @@ int msm_gem_cpu_prep(struct drm_gem_object *obj, 
> > uint32_t op, ktime_t *timeout)
> >  {
> > struct msm_gem_object *msm_obj = to_msm_bo(obj);
> > bool write = !!(op & MSM_PREP_WRITE);
> > -
> > -   if (op & MSM_PREP_NOSYNC) {
> > -   if (!reservation_object_test_signaled_rcu(msm_obj->resv, 
> > write))
> > -   return -EBUSY;
> > -   } else {
> > -   int ret;
> > -
> > -   ret = reservation_object_wait_timeout_rcu(msm_obj->resv, 
> > write,
> > -   true, timeout_to_jiffies(timeout));
> > -   if (ret <= 0)
> > -   return ret == 0 ? -ETIMEDOUT : ret;
> > -   }
> > +   unsigned long remain =
> > +   op & MSG_PREP_NOSYNC ? 0 : timeout_to_jiffies(timeout);
> > +   long ret;
> > +
> > +   ret = reservation_object_wait_timeout_rcu(msm_obj->resv, write,
> > + true,  remain);
> > +   if (ret == 0)
> > +   return remain == 9 ? -EBUSY : -ETIMEDOUT;
> 
> Am sure this must be a typo - 0 instead of 9?

Eek. It's close, but not that close.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre

[PATCH 3/5] drm/msm: Remove call to reservation_object_test_signaled_rcu before wait

2016-08-11 Thread Chris Wilson 
Since fence_wait_timeout_reservation_object_wait_timeout_rcu() with a
timeout of 0 becomes reservation_object_test_signaled_rcu(), we do not
need to handle such conversion in the caller. The only challenge are
those callers that wish to differentiate the error code between the
nonblocking busy check and potentially blocking wait.

Signed-off-by: Chris Wilson 
Cc: Rob Clark 
---
 drivers/gpu/drm/msm/msm_gem.c | 22 ++
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index 6cd4af443139..ab07eb6de25e 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -584,18 +584,16 @@ int msm_gem_cpu_prep(struct drm_gem_object *obj, uint32_t 
op, ktime_t *timeout)
 {
struct msm_gem_object *msm_obj = to_msm_bo(obj);
bool write = !!(op & MSM_PREP_WRITE);
-
-   if (op & MSM_PREP_NOSYNC) {
-   if (!reservation_object_test_signaled_rcu(msm_obj->resv, write))
-   return -EBUSY;
-   } else {
-   int ret;
-
-   ret = reservation_object_wait_timeout_rcu(msm_obj->resv, write,
-   true, timeout_to_jiffies(timeout));
-   if (ret <= 0)
-   return ret == 0 ? -ETIMEDOUT : ret;
-   }
+   unsigned long remain =
+   op & MSG_PREP_NOSYNC ? 0 : timeout_to_jiffies(timeout);
+   long ret;
+
+   ret = reservation_object_wait_timeout_rcu(msm_obj->resv, write,
+ true,  remain);
+   if (ret == 0)
+   return remain == 9 ? -EBUSY : -ETIMEDOUT;
+   else if (ret < 0)
+   return ret;

/* TODO cache maintenance */

-- 
2.8.1