On 8/9/26 21:23, Maíra Canal wrote:
> amdgpu_gem_timeout() converts an absolute deadline in ns into jiffies,
> which is what drm_timeout_abs_to_jiffies() already does for the other
> drivers whose wait UAPI takes a deadline. Use the shared helper and keep
> only the part that is specific to amdgpu.
>
> Two details change along this conversion: the helper rounds up rather than
> truncating, so a deadline less than a tick away now waits for one jiffy
> instead of returning 0. It also uses nsecs_to_jiffies64(), so the
> conversion no longer truncates on 32-bit, where a large deadline could
> previously be reduced to an arbitrary shorter one.
>
> Signed-off-by: Maíra Canal <[email protected]>
>
> ---
>
> As a note, this patch can be merged independently to the AMD tree
> without any dependencies.
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 16 ++--------------
> 1 file changed, 2 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
> index 6a0699746fbc..84b509a484b0 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
> @@ -25,7 +25,6 @@
> * Alex Deucher
> * Jerome Glisse
> */
> -#include <linux/ktime.h>
> #include <linux/module.h>
> #include <linux/overflow.h>
> #include <linux/pagemap.h>
> @@ -40,6 +39,7 @@
> #include <drm/drm_gem_ttm_helper.h>
> #include <drm/ttm/ttm_tt.h>
> #include <drm/drm_syncobj.h>
> +#include <drm/drm_utils.h>
>
> #include "amdgpu.h"
> #include "amdgpu_display.h"
> @@ -622,23 +622,11 @@ int amdgpu_gem_mmap_ioctl(struct drm_device *dev, void
> *data,
> */
> unsigned long amdgpu_gem_timeout(uint64_t timeout_ns)
Please completely nuke that function and replace it with calls to
drm_timeout_abs_to_jiffies().
> {
> - unsigned long timeout_jiffies;
> - ktime_t timeout;
> -
> /* clamp timeout if it's to large */
> if (((int64_t)timeout_ns) < 0)
> return MAX_SCHEDULE_TIMEOUT;
That check was actually never correct at all as far as I can see.
We need to make sure that when timeout_ns is larger than represent-able in long
jiffies (especially on 32bit systems) then MAX_SCHEDULE_TIMEOUT is returned by
drm_timeout_abs_to_jiffies().
And I hope that drm_timeout_abs_to_jiffies() does that correctly already, if
not this seriously needs fixing anyway.
Regards,
Christian.
>
> - timeout = ktime_sub(ns_to_ktime(timeout_ns), ktime_get());
> - if (ktime_to_ns(timeout) < 0)
> - return 0;
> -
> - timeout_jiffies = nsecs_to_jiffies(ktime_to_ns(timeout));
> - /* clamp timeout to avoid unsigned-> signed overflow */
> - if (timeout_jiffies > MAX_SCHEDULE_TIMEOUT)
> - return MAX_SCHEDULE_TIMEOUT - 1;
> -
> - return timeout_jiffies;
> + return drm_timeout_abs_to_jiffies(timeout_ns);
> }
>
> int amdgpu_gem_wait_idle_ioctl(struct drm_device *dev, void *data,
>
