Re: [PATCH] drm/i915: Discard large BIOS framebuffers causing display corruption.

Re: [PATCH] drm/i915: Discard large BIOS framebuffers causing display corruption.

[Orlando Chamberlain]

I haven't observed "display corruption", but on my MacBookPro16,1 the bottom
and right edges of the TTY are not on the screen, so a few lines of text
cannot be seen.

This also occurs on the internal displays of all (as far as I know) other
2018-2020 Intel Macbooks when using the Intel GPU (The 15" and 16" ones
also have an AMDGPU, but this issue occurs when they have the Intel GPU
set as the boot gpu).

There's a similar patch that hasn't been sent upstream that people with these
Macbooks have been using:
https://github.com/aunali1/linux-mbp-arch/blob/master/7001-drm-i915-fbdev-Discard-BIOS-framebuffers-exceeding-h.patch

Cc: Aun-Ali Zaidi <admin@kodeit.net>

--
Thanks,
Orlando

Re: [PATCH] drm/i915: Discard large BIOS framebuffers causing display corruption.

[Aun-Ali Zaidi]

LGTM

—
Aun-Ali Zaidi

> On Jan 8, 2022, at 3:59 AM, Ashish Arora <ashisharora.linux@outlook.com> wrote:
> 
> 
> I believe I forgot to add Aditya to the conversation. So, I am sending the patch as an attachment for those who want to test :)<0001-drm.patch>

Re: [PATCH] drm/i915: Discard large BIOS framebuffers causing display corruption.

[Aditya Garg]

> On 07-Jan-2022, at 6:17 PM, Jani Nikula <jani.nikula@linux.intel.com> wrote:
> 
> On Fri, 07 Jan 2022, Ashish Arora <ashisharora.linux@outlook.com> wrote:
>> From: Ashish Arora <ashisharora.linux@outlook.com>
>> 
>> On certain 4k panels, the BIOS framebuffer is larger than what panel
>> requires causing display corruption. Introduce a check for the same.
> 
> This is quite thin on details. Is there a bug report?
No bug report, but an issue I am facing myself. This patch seems to fix it.
> 
> Moreover, if this is what we want, this should be combined with the
> conditions that follow resulting in a "!=" check instead of separate "<"
> and ">”.
Sending a version 2
> 
> BR,
> Jani.
> 
> 
> 
>> 
>> Signed-off-by: Ashish Arora <ashisharora.linux@outlook.com>
>> ---
>> drivers/gpu/drm/i915/display/intel_fbdev.c | 11 +++++++++++
>> 1 file changed, 11 insertions(+)
>> 
>> diff --git a/drivers/gpu/drm/i915/display/intel_fbdev.c b/drivers/gpu/drm/i915/display/intel_fbdev.c
>> index adc3a81be..f9952e1f8 100644
>> --- a/drivers/gpu/drm/i915/display/intel_fbdev.c
>> +++ b/drivers/gpu/drm/i915/display/intel_fbdev.c
>> @@ -193,6 +193,17 @@ static int intelfb_create(struct drm_fb_helper *helper,
>> 	struct drm_i915_gem_object *obj;
>> 	int ret;
>> 
>> +	if (intel_fb &&
>> +	    (sizes->fb_width < intel_fb->base.width ||
>> +	     sizes->fb_height < intel_fb->base.height)) {
>> +		drm_dbg_kms(&dev_priv->drm,
>> +			    "BIOS fb too large (%dx%d), we require (%dx%d),"
>> +			    " releasing it\n",
>> +			    intel_fb->base.width, intel_fb->base.height,
>> +			    sizes->fb_width, sizes->fb_height);
>> +		drm_framebuffer_put(&intel_fb->base);
>> +		intel_fb = ifbdev->fb = NULL;
>> +	}
>> 	if (intel_fb &&
>> 	    (sizes->fb_width > intel_fb->base.width ||
>> 	     sizes->fb_height > intel_fb->base.height)) {
> 
> -- 
> Jani Nikula, Intel Open Source Graphics Center

Re: [PATCH] drm/i915: Discard large BIOS framebuffers causing display corruption.

[Jani Nikula]

On Fri, 07 Jan 2022, Ashish Arora <ashisharora.linux@outlook.com> wrote:
> From: Ashish Arora <ashisharora.linux@outlook.com>
>
> On certain 4k panels, the BIOS framebuffer is larger than what panel
> requires causing display corruption. Introduce a check for the same.

This is quite thin on details. Is there a bug report?

Moreover, if this is what we want, this should be combined with the
conditions that follow resulting in a "!=" check instead of separate "<"
and ">".

BR,
Jani.



>
> Signed-off-by: Ashish Arora <ashisharora.linux@outlook.com>
> ---
>  drivers/gpu/drm/i915/display/intel_fbdev.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_fbdev.c b/drivers/gpu/drm/i915/display/intel_fbdev.c
> index adc3a81be..f9952e1f8 100644
> --- a/drivers/gpu/drm/i915/display/intel_fbdev.c
> +++ b/drivers/gpu/drm/i915/display/intel_fbdev.c
> @@ -193,6 +193,17 @@ static int intelfb_create(struct drm_fb_helper *helper,
>  	struct drm_i915_gem_object *obj;
>  	int ret;
>  
> +	if (intel_fb &&
> +	    (sizes->fb_width < intel_fb->base.width ||
> +	     sizes->fb_height < intel_fb->base.height)) {
> +		drm_dbg_kms(&dev_priv->drm,
> +			    "BIOS fb too large (%dx%d), we require (%dx%d),"
> +			    " releasing it\n",
> +			    intel_fb->base.width, intel_fb->base.height,
> +			    sizes->fb_width, sizes->fb_height);
> +		drm_framebuffer_put(&intel_fb->base);
> +		intel_fb = ifbdev->fb = NULL;
> +	}
>  	if (intel_fb &&
>  	    (sizes->fb_width > intel_fb->base.width ||
>  	     sizes->fb_height > intel_fb->base.height)) {

-- 
Jani Nikula, Intel Open Source Graphics Center