The introduction of reference counting on the state structures caused
sanitize_watermarks() in i915 to break in the error handling case,
as pointed out by gcc -Wmaybe-uninitialized
drivers/gpu/drm/i915/intel_display.c: In function ‘intel_modeset_init’:
include/drm/drm_atomic.h:224:2: error: ‘state’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
This changes the function back to only drop the reference count
when it was successfully allocated first.
Fixes: 0853695c3ba4 ("drm: Add reference counting to drm_atomic_state")
Cc: Chris Wilson <[email protected]>
Cc: Daniel Vetter <[email protected]>
Signed-off-by: Arnd Bergmann <[email protected]>
---
drivers/gpu/drm/i915/intel_display.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 6d168685bbda..6a26da143aa6 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -16314,7 +16314,7 @@ static void sanitize_watermarks(struct drm_device *dev)
* BIOS-programmed watermarks untouched and hope for the best.
*/
WARN(true, "Could not determine valid watermarks for inherited state\n");
- goto fail;
+ goto put_state;
}
/* Write calculated watermark values back */
@@ -16325,8 +16325,9 @@ static void sanitize_watermarks(struct drm_device *dev)
dev_priv->display.optimize_watermarks(cs);
}
-fail:
+put_state:
drm_atomic_state_put(state);
+fail:
drm_modeset_drop_locks(&ctx);
drm_modeset_acquire_fini(&ctx);
}
--
2.9.0
On Tuesday, 2016-10-18 17:16:23 +0200, Arnd Bergmann wrote:
> The introduction of reference counting on the state structures caused
> sanitize_watermarks() in i915 to break in the error handling case,
> as pointed out by gcc -Wmaybe-uninitialized
>
> drivers/gpu/drm/i915/intel_display.c: In function ‘intel_modeset_init’:
> include/drm/drm_atomic.h:224:2: error: ‘state’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
>
> This changes the function back to only drop the reference count
> when it was successfully allocated first.
>
> Fixes: 0853695c3ba4 ("drm: Add reference counting to drm_atomic_state")
> Cc: Chris Wilson <[email protected]>
> Cc: Daniel Vetter <[email protected]>
> Signed-off-by: Arnd Bergmann <[email protected]>
Reviewed-by: Eric Engestrom <[email protected]>
> ---
> drivers/gpu/drm/i915/intel_display.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 6d168685bbda..6a26da143aa6 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -16314,7 +16314,7 @@ static void sanitize_watermarks(struct drm_device *dev)
> * BIOS-programmed watermarks untouched and hope for the best.
> */
> WARN(true, "Could not determine valid watermarks for inherited state\n");
> - goto fail;
> + goto put_state;
> }
>
> /* Write calculated watermark values back */
> @@ -16325,8 +16325,9 @@ static void sanitize_watermarks(struct drm_device *dev)
> dev_priv->display.optimize_watermarks(cs);
> }
>
> -fail:
> +put_state:
> drm_atomic_state_put(state);
> +fail:
> drm_modeset_drop_locks(&ctx);
> drm_modeset_acquire_fini(&ctx);
> }
> --
> 2.9.0
On Tue, Oct 18, 2016 at 05:16:23PM +0200, Arnd Bergmann wrote:
> The introduction of reference counting on the state structures caused
> sanitize_watermarks() in i915 to break in the error handling case,
> as pointed out by gcc -Wmaybe-uninitialized
>
> drivers/gpu/drm/i915/intel_display.c: In function ‘intel_modeset_init’:
> include/drm/drm_atomic.h:224:2: error: ‘state’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
>
> This changes the function back to only drop the reference count
> when it was successfully allocated first.
>
> Fixes: 0853695c3ba4 ("drm: Add reference counting to drm_atomic_state")
> Cc: Chris Wilson <[email protected]>
> Cc: Daniel Vetter <[email protected]>
> Signed-off-by: Arnd Bergmann <[email protected]>
Yup, missed that it jumps to fail before allocating state.
Function still looks a bit odd, but nvm
Reviewed-by: Chris Wilson <[email protected]>
-Chris
--
Chris Wilson, Intel Open Source Technology Centre
On Tue, Oct 18, 2016 at 04:56:02PM +0100, Chris Wilson wrote:
> On Tue, Oct 18, 2016 at 05:16:23PM +0200, Arnd Bergmann wrote:
> > The introduction of reference counting on the state structures caused
> > sanitize_watermarks() in i915 to break in the error handling case,
> > as pointed out by gcc -Wmaybe-uninitialized
> >
> > drivers/gpu/drm/i915/intel_display.c: In function ‘intel_modeset_init’:
> > include/drm/drm_atomic.h:224:2: error: ‘state’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
> >
> > This changes the function back to only drop the reference count
> > when it was successfully allocated first.
> >
> > Fixes: 0853695c3ba4 ("drm: Add reference counting to drm_atomic_state")
> > Cc: Chris Wilson <[email protected]>
> > Cc: Daniel Vetter <[email protected]>
> > Signed-off-by: Arnd Bergmann <[email protected]>
>
> Yup, missed that it jumps to fail before allocating state.
>
> Function still looks a bit odd, but nvm
> Reviewed-by: Chris Wilson <[email protected]>
Applied to drm-misc, thanks for the patch&review.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch