diff mbox series

[PATCHv1] drm/omap: get fbdev working for manually updated display

Message ID 20210501200050.410704-1-sebastian.reichel@collabora.com (mailing list archive)
State New, archived
Headers show
Series [PATCHv1] drm/omap: get fbdev working for manually updated display | expand

Commit Message

Sebastian Reichel May 1, 2021, 8 p.m. UTC
Running a legacy application, which directly uses /dev/fb0
currently results in display not being refreshed when the
application mmaps the memory instead of calling write().

Deferred IO support will also schedule dirty_work with the
damage collected from the mmap page writes and thus gets
some more legacy applications working.

Delay frequency settings have been taken over from
drm_fb_helper_generic_probe().

Reported-by: Carl Philipp Klemm <philipp@uvos.xyz>
Tested-by: Carl Philipp Klemm <philipp@uvos.xyz>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
Hi,

I still need to fix my Droid 4, so I only compile tested this
myself.

-- Sebastian
---
 drivers/gpu/drm/omapdrm/omap_fbdev.c | 8 ++++++++
 1 file changed, 8 insertions(+)


base-commit: 152d32aa846835987966fd20ee1143b0e05036a0

Comments

Laurent Pinchart May 1, 2021, 8:12 p.m. UTC | #1
On Sat, May 01, 2021 at 10:00:50PM +0200, Sebastian Reichel wrote:
> Running a legacy application, which directly uses /dev/fb0
> currently results in display not being refreshed when the
> application mmaps the memory instead of calling write().
> 
> Deferred IO support will also schedule dirty_work with the
> damage collected from the mmap page writes and thus gets
> some more legacy applications working.
> 
> Delay frequency settings have been taken over from
> drm_fb_helper_generic_probe().
> 
> Reported-by: Carl Philipp Klemm <philipp@uvos.xyz>
> Tested-by: Carl Philipp Klemm <philipp@uvos.xyz>
> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
> ---
> Hi,
> 
> I still need to fix my Droid 4, so I only compile tested this
> myself.
> 
> -- Sebastian
> ---
>  drivers/gpu/drm/omapdrm/omap_fbdev.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/gpu/drm/omapdrm/omap_fbdev.c b/drivers/gpu/drm/omapdrm/omap_fbdev.c
> index 42eac6ad12bd..fc3897d2d7cc 100644
> --- a/drivers/gpu/drm/omapdrm/omap_fbdev.c
> +++ b/drivers/gpu/drm/omapdrm/omap_fbdev.c
> @@ -87,6 +87,11 @@ static const struct fb_ops omap_fb_ops = {
>  	.fb_imageblit = drm_fb_helper_sys_imageblit,
>  };
>  
> +static struct fb_deferred_io omap_fb_defio = {
> +	.delay		= HZ / 20,
> +	.deferred_io	= drm_fb_helper_deferred_io,
> +};

Wish this could be const :-S

> +
>  static int omap_fbdev_create(struct drm_fb_helper *helper,
>  		struct drm_fb_helper_surface_size *sizes)
>  {
> @@ -176,6 +181,9 @@ static int omap_fbdev_create(struct drm_fb_helper *helper,
>  
>  	drm_fb_helper_fill_info(fbi, helper, sizes);
>  
> +	fbi->fbdefio = &omap_fb_defio;
> +	fb_deferred_io_init(fbi);
> +

This looks good to me. Trusting the Tested-by,

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

>  	dev->mode_config.fb_base = dma_addr;
>  
>  	fbi->screen_buffer = omap_gem_vaddr(fbdev->bo);
Tomi Valkeinen May 3, 2021, 8:59 a.m. UTC | #2
On 01/05/2021 23:00, Sebastian Reichel wrote:
> Running a legacy application, which directly uses /dev/fb0
> currently results in display not being refreshed when the
> application mmaps the memory instead of calling write().
> 
> Deferred IO support will also schedule dirty_work with the
> damage collected from the mmap page writes and thus gets
> some more legacy applications working.
> 
> Delay frequency settings have been taken over from
> drm_fb_helper_generic_probe().
> 
> Reported-by: Carl Philipp Klemm <philipp@uvos.xyz>
> Tested-by: Carl Philipp Klemm <philipp@uvos.xyz>
> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
> ---
> Hi,
> 
> I still need to fix my Droid 4, so I only compile tested this
> myself.
> 
> -- Sebastian
> ---
>   drivers/gpu/drm/omapdrm/omap_fbdev.c | 8 ++++++++
>   1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/gpu/drm/omapdrm/omap_fbdev.c b/drivers/gpu/drm/omapdrm/omap_fbdev.c
> index 42eac6ad12bd..fc3897d2d7cc 100644
> --- a/drivers/gpu/drm/omapdrm/omap_fbdev.c
> +++ b/drivers/gpu/drm/omapdrm/omap_fbdev.c
> @@ -87,6 +87,11 @@ static const struct fb_ops omap_fb_ops = {
>   	.fb_imageblit = drm_fb_helper_sys_imageblit,
>   };
>   
> +static struct fb_deferred_io omap_fb_defio = {
> +	.delay		= HZ / 20,
> +	.deferred_io	= drm_fb_helper_deferred_io,
> +};
> +
>   static int omap_fbdev_create(struct drm_fb_helper *helper,
>   		struct drm_fb_helper_surface_size *sizes)
>   {
> @@ -176,6 +181,9 @@ static int omap_fbdev_create(struct drm_fb_helper *helper,
>   
>   	drm_fb_helper_fill_info(fbi, helper, sizes);
>   
> +	fbi->fbdefio = &omap_fb_defio;
> +	fb_deferred_io_init(fbi);
> +
>   	dev->mode_config.fb_base = dma_addr;
>   
>   	fbi->screen_buffer = omap_gem_vaddr(fbdev->bo);
> 
> base-commit: 152d32aa846835987966fd20ee1143b0e05036a0
> 

On DRA76 EVM, with parallel output, this causes cache-flush problem. 
When I run my simple fbtest, which just draws to the fb, I see lots of 
cache-line artifacts.

When I run kmstest (from kms++), I get a flood of list corruptions 
somewhere in omap_gem. Is it related to "Deferred I/O is not compatible 
with SHMEM"?

  Tomi
diff mbox series

Patch

diff --git a/drivers/gpu/drm/omapdrm/omap_fbdev.c b/drivers/gpu/drm/omapdrm/omap_fbdev.c
index 42eac6ad12bd..fc3897d2d7cc 100644
--- a/drivers/gpu/drm/omapdrm/omap_fbdev.c
+++ b/drivers/gpu/drm/omapdrm/omap_fbdev.c
@@ -87,6 +87,11 @@  static const struct fb_ops omap_fb_ops = {
 	.fb_imageblit = drm_fb_helper_sys_imageblit,
 };
 
+static struct fb_deferred_io omap_fb_defio = {
+	.delay		= HZ / 20,
+	.deferred_io	= drm_fb_helper_deferred_io,
+};
+
 static int omap_fbdev_create(struct drm_fb_helper *helper,
 		struct drm_fb_helper_surface_size *sizes)
 {
@@ -176,6 +181,9 @@  static int omap_fbdev_create(struct drm_fb_helper *helper,
 
 	drm_fb_helper_fill_info(fbi, helper, sizes);
 
+	fbi->fbdefio = &omap_fb_defio;
+	fb_deferred_io_init(fbi);
+
 	dev->mode_config.fb_base = dma_addr;
 
 	fbi->screen_buffer = omap_gem_vaddr(fbdev->bo);