[PATCH] firmware/sysfb: Disable sysfb for firmware buffers with unknown parent

[PATCH] firmware/sysfb: Disable sysfb for firmware buffers with unknown parent

[Thomas Zimmermann]

The sysfb framebuffer handling only operates on graphics devices
that provide the system's firmware framebuffer. If that device is
not known, assume that any graphics device has been initialized by
firmware.

Fixes a problem on i915 where sysfb does not release the firmware
framebuffer after the native graphics driver loaded.

Reported-by: Borah, Chaitanya Kumar <chaitanya.kumar.borah@intel.com>
Closes: https://lore.kernel.org/dri-devel/SJ1PR11MB6129EFB8CE63D1EF6D932F94B96F2@SJ1PR11MB6129.namprd11.prod.outlook.com/
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/12160
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: b49420d6a1ae ("video/aperture: optionally match the device in sysfb_disable()")
Cc: Javier Martinez Canillas <javierm@redhat.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Helge Deller <deller@gmx.de>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: dri-devel@lists.freedesktop.org
Cc: Linux regression tracking (Thorsten Leemhuis) <regressions@leemhuis.info>
Cc: <stable@vger.kernel.org> # v6.11+
---
 drivers/firmware/sysfb.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/sysfb.c b/drivers/firmware/sysfb.c
index 02a07d3d0d40..a3df782fa687 100644
--- a/drivers/firmware/sysfb.c
+++ b/drivers/firmware/sysfb.c
@@ -67,9 +67,11 @@ static bool sysfb_unregister(void)
 void sysfb_disable(struct device *dev)
 {
 	struct screen_info *si = &screen_info;
+	struct device *parent;
 
 	mutex_lock(&disable_lock);
-	if (!dev || dev == sysfb_parent_dev(si)) {
+	parent = sysfb_parent_dev(si);
+	if (!dev || !parent || dev == parent) {
 		sysfb_unregister();
 		disabled = true;
 	}
-- 
2.46.0

Re: [PATCH] firmware/sysfb: Disable sysfb for firmware buffers with unknown parent

[Alex Deucher]

On Tue, Sep 24, 2024 at 4:58 AM Thomas Zimmermann <tzimmermann@suse.de> wrote:
>
> The sysfb framebuffer handling only operates on graphics devices
> that provide the system's firmware framebuffer. If that device is
> not known, assume that any graphics device has been initialized by
> firmware.
>
> Fixes a problem on i915 where sysfb does not release the firmware
> framebuffer after the native graphics driver loaded.
>
> Reported-by: Borah, Chaitanya Kumar <chaitanya.kumar.borah@intel.com>
> Closes: https://lore.kernel.org/dri-devel/SJ1PR11MB6129EFB8CE63D1EF6D932F94B96F2@SJ1PR11MB6129.namprd11.prod.outlook.com/
> Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/12160
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> Fixes: b49420d6a1ae ("video/aperture: optionally match the device in sysfb_disable()")
> Cc: Javier Martinez Canillas <javierm@redhat.com>
> Cc: Thomas Zimmermann <tzimmermann@suse.de>
> Cc: Helge Deller <deller@gmx.de>
> Cc: Sam Ravnborg <sam@ravnborg.org>
> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> Cc: Alex Deucher <alexander.deucher@amd.com>
> Cc: dri-devel@lists.freedesktop.org
> Cc: Linux regression tracking (Thorsten Leemhuis) <regressions@leemhuis.info>
> Cc: <stable@vger.kernel.org> # v6.11+

Thanks for fixing this.

Acked-by: Alex Deucher <alexander.deucher@amd.com>

> ---
>  drivers/firmware/sysfb.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/firmware/sysfb.c b/drivers/firmware/sysfb.c
> index 02a07d3d0d40..a3df782fa687 100644
> --- a/drivers/firmware/sysfb.c
> +++ b/drivers/firmware/sysfb.c
> @@ -67,9 +67,11 @@ static bool sysfb_unregister(void)
>  void sysfb_disable(struct device *dev)
>  {
>         struct screen_info *si = &screen_info;
> +       struct device *parent;
>
>         mutex_lock(&disable_lock);
> -       if (!dev || dev == sysfb_parent_dev(si)) {
> +       parent = sysfb_parent_dev(si);
> +       if (!dev || !parent || dev == parent) {
>                 sysfb_unregister();
>                 disabled = true;
>         }
> --
> 2.46.0
>

Re: [PATCH] firmware/sysfb: Disable sysfb for firmware buffers with unknown parent

[Javier Martinez Canillas]

Thomas Zimmermann <tzimmermann@suse.de> writes:

Hello Thomas,

> The sysfb framebuffer handling only operates on graphics devices
> that provide the system's firmware framebuffer. If that device is
> not known, assume that any graphics device has been initialized by
> firmware.
>
> Fixes a problem on i915 where sysfb does not release the firmware
> framebuffer after the native graphics driver loaded.
>
> Reported-by: Borah, Chaitanya Kumar <chaitanya.kumar.borah@intel.com>
> Closes: https://lore.kernel.org/dri-devel/SJ1PR11MB6129EFB8CE63D1EF6D932F94B96F2@SJ1PR11MB6129.namprd11.prod.outlook.com/
> Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/12160
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> Fixes: b49420d6a1ae ("video/aperture: optionally match the device in sysfb_disable()")
> Cc: Javier Martinez Canillas <javierm@redhat.com>
> Cc: Thomas Zimmermann <tzimmermann@suse.de>
> Cc: Helge Deller <deller@gmx.de>
> Cc: Sam Ravnborg <sam@ravnborg.org>
> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> Cc: Alex Deucher <alexander.deucher@amd.com>
> Cc: dri-devel@lists.freedesktop.org
> Cc: Linux regression tracking (Thorsten Leemhuis) <regressions@leemhuis.info>
> Cc: <stable@vger.kernel.org> # v6.11+
> ---
>  drivers/firmware/sysfb.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/firmware/sysfb.c b/drivers/firmware/sysfb.c
> index 02a07d3d0d40..a3df782fa687 100644
> --- a/drivers/firmware/sysfb.c
> +++ b/drivers/firmware/sysfb.c
> @@ -67,9 +67,11 @@ static bool sysfb_unregister(void)
>  void sysfb_disable(struct device *dev)
>  {
>  	struct screen_info *si = &screen_info;
> +	struct device *parent;
>  
>  	mutex_lock(&disable_lock);
> -	if (!dev || dev == sysfb_parent_dev(si)) {
> +	parent = sysfb_parent_dev(si);
> +	if (!dev || !parent || dev == parent) {
>  		sysfb_unregister();
>  		disabled = true;
>  	}

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>

-- 
Best regards,

Javier Martinez Canillas
Core Platforms
Red Hat