[PATCH] drm/i915: tell the user if both KMS and UMS are disabled

[PATCH] drm/i915: tell the user if both KMS and UMS are disabled

[Jani Nikula]

If both KMS is disabled (by i915.modeset=0 or nomodeset parameters) and
UMS is disabled (by CONFIG_DRM_I915_UMS=n, the default), the user might
not be aware his setup is not supported. Inform the users (and, by
extension, the poor i915 developers having to read their dmesgs in bug
reports) why their graphics experience might be lacking.

A similar message was added on the UMS path in
commit e147accbd19f55489dabdcc4dc3551cc3e3f2553
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Thu Oct 10 15:25:37 2013 +0300

    drm/i915: tell the user KMS is required for gen6+

but it won't be reached if CONFIG_DRM_I915_UMS=n since
commit b30324adaf8d2e5950a602bde63030d15a61826f
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Wed Nov 13 22:11:25 2013 +0100

    drm/i915: Deprecated UMS support

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 8949fd26b0ea..f0f690776d45 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1584,6 +1584,8 @@ static int __init i915_init(void)
 	if (!(driver.driver_features & DRIVER_MODESET)) {
 		driver.get_vblank_timestamp = NULL;
 #ifndef CONFIG_DRM_I915_UMS
+		DRM_INFO("Kernel modesetting (KMS) and userspace modesetting (UMS) disabled\n");
+		DRM_INFO("See CONFIG_DRM_I915_UMS, CONFIG_DRM_I915_KMS, nomodeset, and i915.modeset parameters\n");
 		/* Silently fail loading to not upset userspace. */
 		return 0;
 #endif
-- 
1.9.1

Re: [PATCH] drm/i915: tell the user if both KMS and UMS are disabled

[Daniel Vetter]

On Tue, May 27, 2014 at 07:24:12PM +0300, Jani Nikula wrote:
> If both KMS is disabled (by i915.modeset=0 or nomodeset parameters) and
> UMS is disabled (by CONFIG_DRM_I915_UMS=n, the default), the user might
> not be aware his setup is not supported. Inform the users (and, by
> extension, the poor i915 developers having to read their dmesgs in bug
> reports) why their graphics experience might be lacking.
> 
> A similar message was added on the UMS path in
> commit e147accbd19f55489dabdcc4dc3551cc3e3f2553
> Author: Jani Nikula <jani.nikula@intel.com>
> Date:   Thu Oct 10 15:25:37 2013 +0300
> 
>     drm/i915: tell the user KMS is required for gen6+
> 
> but it won't be reached if CONFIG_DRM_I915_UMS=n since
> commit b30324adaf8d2e5950a602bde63030d15a61826f
> Author: Daniel Vetter <daniel.vetter@ffwll.ch>
> Date:   Wed Nov 13 22:11:25 2013 +0100
> 
>     drm/i915: Deprecated UMS support
> 
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Hm, the idea is that this fails _very_ silently so that people only send
us regression reports if they actually notice something. Since if there
are still people out there which needs UMS, we can't yet rip it out.
-Daniel

> ---
>  drivers/gpu/drm/i915/i915_drv.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index 8949fd26b0ea..f0f690776d45 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -1584,6 +1584,8 @@ static int __init i915_init(void)
>  	if (!(driver.driver_features & DRIVER_MODESET)) {
>  		driver.get_vblank_timestamp = NULL;
>  #ifndef CONFIG_DRM_I915_UMS
> +		DRM_INFO("Kernel modesetting (KMS) and userspace modesetting (UMS) disabled\n");
> +		DRM_INFO("See CONFIG_DRM_I915_UMS, CONFIG_DRM_I915_KMS, nomodeset, and i915.modeset parameters\n");
>  		/* Silently fail loading to not upset userspace. */
>  		return 0;
>  #endif
> -- 
> 1.9.1
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [PATCH] drm/i915: tell the user if both KMS and UMS are disabled

[Jani Nikula]

On Tue, 27 May 2014, Daniel Vetter <daniel@ffwll.ch> wrote:
> On Tue, May 27, 2014 at 07:24:12PM +0300, Jani Nikula wrote:
>> If both KMS is disabled (by i915.modeset=0 or nomodeset parameters) and
>> UMS is disabled (by CONFIG_DRM_I915_UMS=n, the default), the user might
>> not be aware his setup is not supported. Inform the users (and, by
>> extension, the poor i915 developers having to read their dmesgs in bug
>> reports) why their graphics experience might be lacking.
>> 
>> A similar message was added on the UMS path in
>> commit e147accbd19f55489dabdcc4dc3551cc3e3f2553
>> Author: Jani Nikula <jani.nikula@intel.com>
>> Date:   Thu Oct 10 15:25:37 2013 +0300
>> 
>>     drm/i915: tell the user KMS is required for gen6+
>> 
>> but it won't be reached if CONFIG_DRM_I915_UMS=n since
>> commit b30324adaf8d2e5950a602bde63030d15a61826f
>> Author: Daniel Vetter <daniel.vetter@ffwll.ch>
>> Date:   Wed Nov 13 22:11:25 2013 +0100
>> 
>>     drm/i915: Deprecated UMS support
>> 
>> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>
> Hm, the idea is that this fails _very_ silently so that people only send
> us regression reports if they actually notice something. Since if there
> are still people out there which needs UMS, we can't yet rip it out.

My gut feeling from bug reports is that, since CONFIG_DRM_I915_UMS now
defaults to n, we mostly end up here because users have issues with KMS
and try nomodeset as a workaround. Is this silent enough, same commit
message:

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 8949fd26b0ea..ca46e6cf4b99 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1585,6 +1585,7 @@ static int __init i915_init(void)
 		driver.get_vblank_timestamp = NULL;
 #ifndef CONFIG_DRM_I915_UMS
 		/* Silently fail loading to not upset userspace. */
+		DRM_DEBUG_DRIVER("KMS and UMS disabled.\n");
 		return 0;
 #endif
 	}

BR,
Jani.


> -Daniel
>
>> ---
>>  drivers/gpu/drm/i915/i915_drv.c | 2 ++
>>  1 file changed, 2 insertions(+)
>> 
>> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
>> index 8949fd26b0ea..f0f690776d45 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.c
>> +++ b/drivers/gpu/drm/i915/i915_drv.c
>> @@ -1584,6 +1584,8 @@ static int __init i915_init(void)
>>  	if (!(driver.driver_features & DRIVER_MODESET)) {
>>  		driver.get_vblank_timestamp = NULL;
>>  #ifndef CONFIG_DRM_I915_UMS
>> +		DRM_INFO("Kernel modesetting (KMS) and userspace modesetting (UMS) disabled\n");
>> +		DRM_INFO("See CONFIG_DRM_I915_UMS, CONFIG_DRM_I915_KMS, nomodeset, and i915.modeset parameters\n");
>>  		/* Silently fail loading to not upset userspace. */
>>  		return 0;
>>  #endif
>> -- 
>> 1.9.1
>> 
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx@lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch

-- 
Jani Nikula, Intel Open Source Technology Center

[PATCH v2] drm/i915: tell the user if both KMS and UMS are disabled

[Jani Nikula]

If both KMS is disabled (by i915.modeset=0 or nomodeset parameters) and
UMS is disabled (by CONFIG_DRM_I915_UMS=n, the default), the user might
not be aware his setup is not supported. Inform the users (and, by
extension, the poor i915 developers having to read their dmesgs in bug
reports) why their graphics experience might be lacking.

A similar message was added on the UMS path in
commit e147accbd19f55489dabdcc4dc3551cc3e3f2553
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Thu Oct 10 15:25:37 2013 +0300

    drm/i915: tell the user KMS is required for gen6+

but it won't be reached if CONFIG_DRM_I915_UMS=n since
commit b30324adaf8d2e5950a602bde63030d15a61826f
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Wed Nov 13 22:11:25 2013 +0100

    drm/i915: Deprecated UMS support

v2: Use DRM_DEBUG_DRIVER.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index b6d2a8f96278..8e58083ffb11 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1576,6 +1576,7 @@ static int __init i915_init(void)
 		driver.get_vblank_timestamp = NULL;
 #ifndef CONFIG_DRM_I915_UMS
 		/* Silently fail loading to not upset userspace. */
+		DRM_DEBUG_DRIVER("KMS and UMS disabled.\n");
 		return 0;
 #endif
 	}
-- 
1.9.1

Re: [PATCH v2] drm/i915: tell the user if both KMS and UMS are disabled

[Daniel Vetter]

On Mon, Jun 02, 2014 at 04:58:30PM +0300, Jani Nikula wrote:
> If both KMS is disabled (by i915.modeset=0 or nomodeset parameters) and
> UMS is disabled (by CONFIG_DRM_I915_UMS=n, the default), the user might
> not be aware his setup is not supported. Inform the users (and, by
> extension, the poor i915 developers having to read their dmesgs in bug
> reports) why their graphics experience might be lacking.
> 
> A similar message was added on the UMS path in
> commit e147accbd19f55489dabdcc4dc3551cc3e3f2553
> Author: Jani Nikula <jani.nikula@intel.com>
> Date:   Thu Oct 10 15:25:37 2013 +0300
> 
>     drm/i915: tell the user KMS is required for gen6+
> 
> but it won't be reached if CONFIG_DRM_I915_UMS=n since
> commit b30324adaf8d2e5950a602bde63030d15a61826f
> Author: Daniel Vetter <daniel.vetter@ffwll.ch>
> Date:   Wed Nov 13 22:11:25 2013 +0100
> 
>     drm/i915: Deprecated UMS support
> 
> v2: Use DRM_DEBUG_DRIVER.
> 
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Queued for -next, thanks for the patch. I'll shuffle it into the 3.16 pile
when I get around to that.
-Daniel
> ---
>  drivers/gpu/drm/i915/i915_drv.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index b6d2a8f96278..8e58083ffb11 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -1576,6 +1576,7 @@ static int __init i915_init(void)
>  		driver.get_vblank_timestamp = NULL;
>  #ifndef CONFIG_DRM_I915_UMS
>  		/* Silently fail loading to not upset userspace. */
> +		DRM_DEBUG_DRIVER("KMS and UMS disabled.\n");
>  		return 0;
>  #endif
>  	}
> -- 
> 1.9.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch