On Tue, Jun 3, 2014 at 9:33 AM, Daniel Vetter <daniel@xxxxxxxx> wrote:
> On Fri, May 30, 2014 at 01:12:10PM -0400, Rob Clark wrote:
>> All drm_fb_helper_restore_fbdev_mode() call sites, save one, do the same
>> locking. Simplify this into drm_fb_helper_restore_fbdev_mode_unlocked().
>>
>> Signed-off-by: Rob Clark <robdclark@xxxxxxxxx>
>
> Presuming I'm not blind the last such user is in the fb helper itself for
> the panic handler. Should we drop the EXPORT_SYMBOL for the helper?
only reason I could think of for leaving (and for keeping the
_unlocked suffix) was to catch merge issues.. leaving same name but
with locking removed, it would compile fine and fail at runtime ;-)
I can remove the prototype and EXPORT_SYMBOL I suppose just to be
extra sure we catch everything (because once we start doing things
atomically, it won't work if drivers still wrap it with their own
_lock_all())
BR,
-R
> If we do that we might as well drop the _unlocked prefix and just remove
> locking from drivers ...
> -Daniel
>
>> ---
>> drivers/gpu/drm/armada/armada_fbdev.c | 4 +--
>> drivers/gpu/drm/drm_fb_cma_helper.c | 9 ++----
>> drivers/gpu/drm/drm_fb_helper.c | 51 +++++++++++++++++++++++--------
>> drivers/gpu/drm/exynos/exynos_drm_fbdev.c | 4 +--
>> drivers/gpu/drm/gma500/psb_drv.c | 4 +--
>> drivers/gpu/drm/i915/intel_fbdev.c | 6 +---
>> drivers/gpu/drm/msm/msm_drv.c | 7 ++---
>> drivers/gpu/drm/omapdrm/omap_drv.c | 4 +--
>> drivers/gpu/drm/tegra/fb.c | 7 ++---
>> include/drm/drm_fb_helper.h | 1 +
>> 10 files changed, 50 insertions(+), 47 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/armada/armada_fbdev.c b/drivers/gpu/drm/armada/armada_fbdev.c
>> index 948cb14..fd166f5 100644
>> --- a/drivers/gpu/drm/armada/armada_fbdev.c
>> +++ b/drivers/gpu/drm/armada/armada_fbdev.c
>> @@ -181,10 +181,8 @@ void armada_fbdev_lastclose(struct drm_device *dev)
>> {
>> struct armada_private *priv = dev->dev_private;
>>
>> - drm_modeset_lock_all(dev);
>> if (priv->fbdev)
>> - drm_fb_helper_restore_fbdev_mode(priv->fbdev);
>> - drm_modeset_unlock_all(dev);
>> + drm_fb_helper_restore_fbdev_mode_unlocked(priv->fbdev);
>> }
>>
>> void armada_fbdev_fini(struct drm_device *dev)
>> diff --git a/drivers/gpu/drm/drm_fb_cma_helper.c b/drivers/gpu/drm/drm_fb_cma_helper.c
>> index 61b5a47..f27c883 100644
>> --- a/drivers/gpu/drm/drm_fb_cma_helper.c
>> +++ b/drivers/gpu/drm/drm_fb_cma_helper.c
>> @@ -429,13 +429,8 @@ EXPORT_SYMBOL_GPL(drm_fbdev_cma_fini);
>> */
>> void drm_fbdev_cma_restore_mode(struct drm_fbdev_cma *fbdev_cma)
>> {
>> - if (fbdev_cma) {
>> - struct drm_device *dev = fbdev_cma->fb_helper.dev;
>> -
>> - drm_modeset_lock_all(dev);
>> - drm_fb_helper_restore_fbdev_mode(&fbdev_cma->fb_helper);
>> - drm_modeset_unlock_all(dev);
>> - }
>> + if (fbdev_cma)
>> + drm_fb_helper_restore_fbdev_mode_unlocked(&fbdev_cma->fb_helper);
>> }
>> EXPORT_SYMBOL_GPL(drm_fbdev_cma_restore_mode);
>>
>> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
>> index b891f4c..dc861a1 100644
>> --- a/drivers/gpu/drm/drm_fb_helper.c
>> +++ b/drivers/gpu/drm/drm_fb_helper.c
>> @@ -273,15 +273,7 @@ int drm_fb_helper_debug_leave(struct fb_info *info)
>> }
>> EXPORT_SYMBOL(drm_fb_helper_debug_leave);
>>
>> -/**
>> - * drm_fb_helper_restore_fbdev_mode - restore fbdev configuration
>> - * @fb_helper: fbcon to restore
>> - *
>> - * This should be called from driver's drm ->lastclose callback
>> - * when implementing an fbcon on top of kms using this helper. This ensures that
>> - * the user isn't greeted with a black screen when e.g. X dies.
>> - */
>> -bool drm_fb_helper_restore_fbdev_mode(struct drm_fb_helper *fb_helper)
>> +static bool restore_fbdev_mode(struct drm_fb_helper *fb_helper)
>> {
>> struct drm_device *dev = fb_helper->dev;
>> struct drm_plane *plane;
>> @@ -311,8 +303,44 @@ bool drm_fb_helper_restore_fbdev_mode(struct drm_fb_helper *fb_helper)
>> }
>> return error;
>> }
>> +/**
>> + * drm_fb_helper_restore_fbdev_mode - restore fbdev configuration
>> + * @fb_helper: fbcon to restore
>> + * @lockless: true in drm_fb_helper_force_kernel_mode() path, to avoid
>> + * blocking in panic case, everywhere else should use false
>> + *
>> + * This should be called from driver's drm ->lastclose callback
>> + * when implementing an fbcon on top of kms using this helper. This ensures that
>> + * the user isn't greeted with a black screen when e.g. X dies.
>> + *
>> + * Use this variant if you need to bypass locking (panic), or already
>> + * hold all modeset locks. Otherwise use drm_fb_helper_restore_fbdev_mode_unlocked()
>> + */
>> +bool drm_fb_helper_restore_fbdev_mode(struct drm_fb_helper *fb_helper)
>> +{
>> + return restore_fbdev_mode(fb_helper);
>> +}
>> EXPORT_SYMBOL(drm_fb_helper_restore_fbdev_mode);
>>
>> +/**
>> + * drm_fb_helper_restore_fbdev_mode_unlocked - restore fbdev configuration
>> + * @fb_helper: fbcon to restore
>> + *
>> + * This should be called from driver's drm ->lastclose callback
>> + * when implementing an fbcon on top of kms using this helper. This ensures that
>> + * the user isn't greeted with a black screen when e.g. X dies.
>> + */
>> +bool drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
>> +{
>> + struct drm_device *dev = fb_helper->dev;
>> + bool ret;
>> + drm_modeset_lock_all(dev);
>> + ret = restore_fbdev_mode(fb_helper);
>> + drm_modeset_unlock_all(dev);
>> + return ret;
>> +}
>> +EXPORT_SYMBOL(drm_fb_helper_restore_fbdev_mode_unlocked);
>> +
>> /*
>> * restore fbcon display for all kms driver's using this helper, used for sysrq
>> * and panic handling.
>> @@ -824,7 +852,6 @@ EXPORT_SYMBOL(drm_fb_helper_check_var);
>> int drm_fb_helper_set_par(struct fb_info *info)
>> {
>> struct drm_fb_helper *fb_helper = info->par;
>> - struct drm_device *dev = fb_helper->dev;
>> struct fb_var_screeninfo *var = &info->var;
>>
>> if (var->pixclock != 0) {
>> @@ -832,9 +859,7 @@ int drm_fb_helper_set_par(struct fb_info *info)
>> return -EINVAL;
>> }
>>
>> - drm_modeset_lock_all(dev);
>> - drm_fb_helper_restore_fbdev_mode(fb_helper);
>> - drm_modeset_unlock_all(dev);
>> + drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper);
>>
>> if (fb_helper->delayed_hotplug) {
>> fb_helper->delayed_hotplug = false;
>> diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
>> index addbf75..93e7ba6 100644
>> --- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
>> +++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
>> @@ -375,7 +375,5 @@ void exynos_drm_fbdev_restore_mode(struct drm_device *dev)
>> if (!private || !private->fb_helper)
>> return;
>>
>> - drm_modeset_lock_all(dev);
>> - drm_fb_helper_restore_fbdev_mode(private->fb_helper);
>> - drm_modeset_unlock_all(dev);
>> + drm_fb_helper_restore_fbdev_mode_unlocked(private->fb_helper);
>> }
>> diff --git a/drivers/gpu/drm/gma500/psb_drv.c b/drivers/gpu/drm/gma500/psb_drv.c
>> index 0a3101a..59ea45e 100644
>> --- a/drivers/gpu/drm/gma500/psb_drv.c
>> +++ b/drivers/gpu/drm/gma500/psb_drv.c
>> @@ -112,11 +112,9 @@ static void psb_driver_lastclose(struct drm_device *dev)
>> struct drm_psb_private *dev_priv = dev->dev_private;
>> struct psb_fbdev *fbdev = dev_priv->fbdev;
>>
>> - drm_modeset_lock_all(dev);
>> - ret = drm_fb_helper_restore_fbdev_mode(&fbdev->psb_fb_helper);
>> + ret = drm_fb_helper_restore_fbdev_mode_unlocked(&fbdev->psb_fb_helper);
>> if (ret)
>> DRM_DEBUG("failed to restore crtc mode\n");
>> - drm_modeset_unlock_all(dev);
>>
>> return;
>> }
>> diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
>> index fce4a0d..f8258ab 100644
>> --- a/drivers/gpu/drm/i915/intel_fbdev.c
>> +++ b/drivers/gpu/drm/i915/intel_fbdev.c
>> @@ -683,11 +683,7 @@ void intel_fbdev_restore_mode(struct drm_device *dev)
>> if (!dev_priv->fbdev)
>> return;
>>
>> - drm_modeset_lock_all(dev);
>> -
>> - ret = drm_fb_helper_restore_fbdev_mode(&dev_priv->fbdev->helper);
>> + ret = drm_fb_helper_restore_fbdev_mode_unlocked(&dev_priv->fbdev->helper);
>> if (ret)
>> DRM_DEBUG("failed to restore crtc mode\n");
>> -
>> - drm_modeset_unlock_all(dev);
>> }
>> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
>> index 50ec1be..afedd8b 100644
>> --- a/drivers/gpu/drm/msm/msm_drv.c
>> +++ b/drivers/gpu/drm/msm/msm_drv.c
>> @@ -382,11 +382,8 @@ static void msm_preclose(struct drm_device *dev, struct drm_file *file)
>> static void msm_lastclose(struct drm_device *dev)
>> {
>> struct msm_drm_private *priv = dev->dev_private;
>> - if (priv->fbdev) {
>> - drm_modeset_lock_all(dev);
>> - drm_fb_helper_restore_fbdev_mode(priv->fbdev);
>> - drm_modeset_unlock_all(dev);
>> - }
>> + if (priv->fbdev)
>> + drm_fb_helper_restore_fbdev_mode_unlocked(priv->fbdev);
>> }
>>
>> static irqreturn_t msm_irq(int irq, void *arg)
>> diff --git a/drivers/gpu/drm/omapdrm/omap_drv.c b/drivers/gpu/drm/omapdrm/omap_drv.c
>> index c8270e4..002b972 100644
>> --- a/drivers/gpu/drm/omapdrm/omap_drv.c
>> +++ b/drivers/gpu/drm/omapdrm/omap_drv.c
>> @@ -588,9 +588,7 @@ static void dev_lastclose(struct drm_device *dev)
>> }
>> }
>>
>> - drm_modeset_lock_all(dev);
>> - ret = drm_fb_helper_restore_fbdev_mode(priv->fbdev);
>> - drm_modeset_unlock_all(dev);
>> + ret = drm_fb_helper_restore_fbdev_mode_unlocked(priv->fbdev);
>> if (ret)
>> DBG("failed to restore crtc mode");
>> }
>> diff --git a/drivers/gpu/drm/tegra/fb.c b/drivers/gpu/drm/tegra/fb.c
>> index f7fca09..9798a70 100644
>> --- a/drivers/gpu/drm/tegra/fb.c
>> +++ b/drivers/gpu/drm/tegra/fb.c
>> @@ -346,11 +346,8 @@ static void tegra_fbdev_free(struct tegra_fbdev *fbdev)
>>
>> void tegra_fbdev_restore_mode(struct tegra_fbdev *fbdev)
>> {
>> - if (fbdev) {
>> - drm_modeset_lock_all(fbdev->base.dev);
>> - drm_fb_helper_restore_fbdev_mode(&fbdev->base);
>> - drm_modeset_unlock_all(fbdev->base.dev);
>> - }
>> + if (fbdev)
>> + drm_fb_helper_restore_fbdev_mode_unlocked(&fbdev->base);
>> }
>>
>> static void tegra_fb_output_poll_changed(struct drm_device *drm)
>> diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
>> index 6e622f7..0630b51 100644
>> --- a/include/drm/drm_fb_helper.h
>> +++ b/include/drm/drm_fb_helper.h
>> @@ -109,6 +109,7 @@ int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
>> struct fb_info *info);
>>
>> bool drm_fb_helper_restore_fbdev_mode(struct drm_fb_helper *fb_helper);
>> +bool drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper);
>> void drm_fb_helper_fill_var(struct fb_info *info, struct drm_fb_helper *fb_helper,
>> uint32_t fb_width, uint32_t fb_height);
>> void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
>> --
>> 1.9.3
>>
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch
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