From e2f8fd74ec1bf15cb2abc1b11f7d9fa09581024e Mon Sep 17 00:00:00 2001 From: Tomi Valkeinen Date: Wed, 2 Apr 2014 14:31:57 +0300 Subject: [PATCH] drm/omap: fix race issue when unloading omapdrm At module unload, omap_fbdev_free() gets called which releases the framebuffers. However, the framebuffers are still used by crtcs, and will be released only later at vsync. The driver doesn't wait for this, and goes on to release the rest of the resources, which often causes a crash. This patchs adds a omap_crtc_flush() function which waits until the crtc has finished with its apply queue and page flips. The function utilizes a simple polling while-loop, as the performance is not an issue here. Signed-off-by: Tomi Valkeinen Reviewed-by: Rob Clark --- drivers/gpu/drm/omapdrm/omap_crtc.c | 19 +++++++++++++++++++ drivers/gpu/drm/omapdrm/omap_drv.c | 6 ++++++ drivers/gpu/drm/omapdrm/omap_drv.h | 1 + 3 files changed, 26 insertions(+) diff --git a/drivers/gpu/drm/omapdrm/omap_crtc.c b/drivers/gpu/drm/omapdrm/omap_crtc.c index 0acbe62901d9..161a74a3ac5e 100644 --- a/drivers/gpu/drm/omapdrm/omap_crtc.c +++ b/drivers/gpu/drm/omapdrm/omap_crtc.c @@ -621,6 +621,25 @@ static void omap_crtc_post_apply(struct omap_drm_apply *apply) /* nothing needed for post-apply */ } +void omap_crtc_flush(struct drm_crtc *crtc) +{ + struct omap_crtc *omap_crtc = to_omap_crtc(crtc); + int loops = 0; + + while (!list_empty(&omap_crtc->pending_applies) || + !list_empty(&omap_crtc->queued_applies) || + omap_crtc->event || omap_crtc->old_fb) { + + if (++loops > 10) { + dev_err(crtc->dev->dev, + "omap_crtc_flush() timeout\n"); + break; + } + + schedule_timeout_uninterruptible(msecs_to_jiffies(20)); + } +} + static const char *channel_names[] = { [OMAP_DSS_CHANNEL_LCD] = "lcd", [OMAP_DSS_CHANNEL_DIGIT] = "tv", diff --git a/drivers/gpu/drm/omapdrm/omap_drv.c b/drivers/gpu/drm/omapdrm/omap_drv.c index f16a07d1668d..c8270e4b26f3 100644 --- a/drivers/gpu/drm/omapdrm/omap_drv.c +++ b/drivers/gpu/drm/omapdrm/omap_drv.c @@ -513,12 +513,18 @@ static int dev_load(struct drm_device *dev, unsigned long flags) static int dev_unload(struct drm_device *dev) { struct omap_drm_private *priv = dev->dev_private; + int i; DBG("unload: dev=%p", dev); drm_kms_helper_poll_fini(dev); omap_fbdev_free(dev); + + /* flush crtcs so the fbs get released */ + for (i = 0; i < priv->num_crtcs; i++) + omap_crtc_flush(priv->crtcs[i]); + omap_modeset_free(dev); omap_gem_deinit(dev); diff --git a/drivers/gpu/drm/omapdrm/omap_drv.h b/drivers/gpu/drm/omapdrm/omap_drv.h index 428b2981fd68..284b80fc3c54 100644 --- a/drivers/gpu/drm/omapdrm/omap_drv.h +++ b/drivers/gpu/drm/omapdrm/omap_drv.h @@ -163,6 +163,7 @@ void omap_crtc_pre_init(void); void omap_crtc_pre_uninit(void); struct drm_crtc *omap_crtc_init(struct drm_device *dev, struct drm_plane *plane, enum omap_channel channel, int id); +void omap_crtc_flush(struct drm_crtc *crtc); struct drm_plane *omap_plane_init(struct drm_device *dev, int plane_id, bool private_plane); -- 2.34.1