Re: [PATCH v1 05/11] drm/vblank: drop use of DRM_WAIT_ON()

From: Sean Paul <sean@poorly.run>
To: Sam Ravnborg <sam@ravnborg.org>
Cc: "David Airlie" <airlied@linux.ie>,
	"Liviu Dudau" <Liviu.Dudau@arm.com>,
	dri-devel@lists.freedesktop.org,
	"Maxime Ripard" <maxime.ripard@bootlin.com>,
	"Thierry Reding" <treding@nvidia.com>,
	"Jani Nikula" <jani.nikula@intel.com>,
	"Intel Graphics Development" <intel-gfx@lists.freedesktop.org>,
	linux-mediatek@lists.infradead.org,
	"Matthias Brugger" <matthias.bgg@gmail.com>,
	"Sean Paul" <sean@poorly.run>,
	linux-arm-kernel@lists.infradead.org,
	"Boris Brezillon" <bbrezillon@kernel.org>,
	"Thomas Zimmermann" <tzimmermann@suse.de>,
	"Christian König" <christian.koenig@amd.com>
Subject: Re: [PATCH v1 05/11] drm/vblank: drop use of DRM_WAIT_ON()
Date: Thu, 18 Jul 2019 13:50:58 -0400	[thread overview]
Message-ID: <20190718175058.GH31819@art_vandelay> (raw)
In-Reply-To: <20190718161507.2047-6-sam@ravnborg.org>

On Thu, Jul 18, 2019 at 06:15:01PM +0200, Sam Ravnborg wrote:
> DRM_WAIT_ON() is from the deprecated drm_os_linux header and
> the modern replacement is the wait_event_*.
> 
> The return values differ, so a conversion is needed to
> keep the original interface towards userspace.
> Introduced a switch/case to make code obvious and to allow
> different debug prints depending on the result.
> 
> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

Reviewed-by: Sean Paul <sean@poorly.run>

> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> Cc: Maxime Ripard <maxime.ripard@bootlin.com>
> Cc: Sean Paul <sean@poorly.run>
> Cc: David Airlie <airlied@linux.ie>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> ---
>  drivers/gpu/drm/drm_vblank.c | 29 ++++++++++++++++++++---------
>  1 file changed, 20 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
> index 603ab105125d..8e9ac187500e 100644
> --- a/drivers/gpu/drm/drm_vblank.c
> +++ b/drivers/gpu/drm/drm_vblank.c
> @@ -31,7 +31,6 @@
>  #include <drm/drm_drv.h>
>  #include <drm/drm_framebuffer.h>
>  #include <drm/drm_print.h>
> -#include <drm/drm_os_linux.h>
>  #include <drm/drm_vblank.h>
>  
>  #include "drm_internal.h"
> @@ -1672,19 +1671,31 @@ int drm_wait_vblank_ioctl(struct drm_device *dev, void *data,
>  	if (req_seq != seq) {
>  		DRM_DEBUG("waiting on vblank count %llu, crtc %u\n",
>  			  req_seq, pipe);
> -		DRM_WAIT_ON(ret, vblank->queue, 3 * HZ,
> -			    vblank_passed(drm_vblank_count(dev, pipe),
> -					  req_seq) ||
> -			    !READ_ONCE(vblank->enabled));
> +		ret = wait_event_interruptible_timeout(vblank->queue,
> +			vblank_passed(drm_vblank_count(dev, pipe), req_seq) ||
> +				      !READ_ONCE(vblank->enabled),
> +			msecs_to_jiffies(3000));
>  	}
>  
> -	if (ret != -EINTR) {
> +	switch (ret) {
> +	case 0:
> +		/* timeout */
> +		ret = -EBUSY;
>  		drm_wait_vblank_reply(dev, pipe, &vblwait->reply);
> -
> -		DRM_DEBUG("crtc %d returning %u to client\n",
> +		DRM_DEBUG("timeout waiting for vblank. crtc %d returning %u to client\n",
>  			  pipe, vblwait->reply.sequence);
> -	} else {
> +		break;
> +	case -ERESTARTSYS:
> +		/* interrupted by signal */
> +		ret = -EINTR;
>  		DRM_DEBUG("crtc %d vblank wait interrupted by signal\n", pipe);
> +		break;
> +	default:
> +		ret = 0;
> +		drm_wait_vblank_reply(dev, pipe, &vblwait->reply);
> +		DRM_DEBUG("crtc %d returning %u to client\n",
> +			  pipe, vblwait->reply.sequence);
> +		break;
>  	}
>  
>  done:
> -- 
> 2.20.1
> 

-- 
Sean Paul, Software Engineer, Google / Chromium OS
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel