In some cases I've been seeing a race where two framebuffers would be initialized, as kirin_fbdev_output_poll_changed() might get called quickly in succession, resulting in the initialization happening twice. This could cause the system to boot up with a blank screen.
This patch adds a simple mutex to serialize it and seems to avoid the race. Suggestions or feedback would be greatly appreciated! Cc: Xinliang Liu <[email protected]> Cc: Rongrong Zou <[email protected]> Cc: Xinwei Kong <[email protected]> Cc: Chen Feng <[email protected]> Cc: David Airlie <[email protected]> Cc: Daniel Vetter <[email protected]> Cc: Sean Paul <[email protected]> Cc: [email protected] Signed-off-by: John Stultz <[email protected]> --- drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.c | 4 ++++ drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.h | 1 + 2 files changed, 5 insertions(+) diff --git a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.c b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.c index 7ec93ae..b83556a 100644 --- a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.c +++ b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.c @@ -55,6 +55,7 @@ static void kirin_fbdev_output_poll_changed(struct drm_device *dev) { struct kirin_drm_private *priv = dev->dev_private; + mutex_lock(&priv->fb_lock); if (priv->fbdev) { drm_fbdev_cma_hotplug_event(priv->fbdev); } else { @@ -63,6 +64,7 @@ static void kirin_fbdev_output_poll_changed(struct drm_device *dev) if (IS_ERR(priv->fbdev)) priv->fbdev = NULL; } + mutex_unlock(&priv->fb_lock); } #endif @@ -95,6 +97,8 @@ static int kirin_drm_kms_init(struct drm_device *dev) if (!priv) return -ENOMEM; + mutex_init(&priv->fb_lock); + dev->dev_private = priv; dev_set_drvdata(dev->dev, dev); diff --git a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.h b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.h index 7f60c649..9b6d2b1 100644 --- a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.h +++ b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.h @@ -23,6 +23,7 @@ struct kirin_drm_private { #ifdef CONFIG_DRM_FBDEV_EMULATION struct drm_fbdev_cma *fbdev; #endif + struct mutex fb_lock; }; extern const struct kirin_dc_ops ade_dc_ops; -- 2.7.4 _______________________________________________ dri-devel mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/dri-devel
