Hi Maxime, Thank you for the patch. On Thursday 02 Feb 2017 11:31:56 Maxime Ripard wrote: > From: Xinliang Liu <xinliang.liu@xxxxxxxxxx> > > This patch add a config to support to create multi buffer for cma fbdev. > Such as double buffer and triple buffer. > > Cma fbdev is convient to add a legency fbdev. And still many Android > devices use fbdev now and at least double buffer is needed for these > Android devices, so that a buffer flip can be operated. It will need > some time for Android device vendors to abondon legency fbdev. So multi > buffer for fbdev is needed. How exactly do we expect Android to move away from fbdev if we add features to the fbdev compat layer ? I'd much rather make it clear to them that fbdev is a thing from the past and that they'd better migrate now. > Signed-off-by: Xinliang Liu <xinliang.liu@xxxxxxxxxx> > [s.christ@xxxxxxxxx: Picking patch from > https://lkml.org/lkml/2015/9/14/188] > Signed-off-by: Stefan Christ <s.christ@xxxxxxxxx> > Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> > --- > drivers/gpu/drm/Kconfig | 8 ++++++++ > drivers/gpu/drm/drm_fb_cma_helper.c | 8 +++++++- > 2 files changed, 15 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig > index ebfe8404c25f..2ca9bb26a4e4 100644 > --- a/drivers/gpu/drm/Kconfig > +++ b/drivers/gpu/drm/Kconfig > @@ -121,6 +121,14 @@ config DRM_KMS_CMA_HELPER > help > Choose this if you need the KMS CMA helper functions > > +config DRM_CMA_FBDEV_BUFFER_NUM > + int "Cma Fbdev Buffer Number" > + depends on DRM_KMS_CMA_HELPER > + default 1 > + help > + Defines the buffer number of cma fbdev. Default is one buffer. > + For double buffer please set to 2 and 3 for triple buffer. > + > source "drivers/gpu/drm/i2c/Kconfig" > > source "drivers/gpu/drm/arm/Kconfig" > diff --git a/drivers/gpu/drm/drm_fb_cma_helper.c > b/drivers/gpu/drm/drm_fb_cma_helper.c index 81b3558302b5..e3f8b9e720a0 > 100644 > --- a/drivers/gpu/drm/drm_fb_cma_helper.c > +++ b/drivers/gpu/drm/drm_fb_cma_helper.c > @@ -411,6 +411,12 @@ static void drm_fbdev_cma_defio_fini(struct fb_info > *fbi) kfree(fbi->fbops); > } > > +static int fbdev_num_buffers = CONFIG_DRM_CMA_FBDEV_BUFFER_NUM; > +module_param(fbdev_num_buffers, int, 0444); > +MODULE_PARM_DESC(fbdev_num_buffers, > + "Number of frame buffers to allocate [default=" > + __MODULE_STRING(CONFIG_DRM_CMA_FBDEV_BUFFER_NUM) "]"); > + > /* > * For use in a (struct drm_fb_helper_funcs *)->fb_probe callback function > that * needs custom struct drm_framebuffer_funcs, like dirty() for > deferred_io use. @@ -437,7 +443,7 @@ int > drm_fbdev_cma_create_with_funcs(struct drm_fb_helper *helper, > bytes_per_pixel = DIV_ROUND_UP(sizes->surface_bpp, 8); > > mode_cmd.width = sizes->surface_width; > - mode_cmd.height = sizes->surface_height; > + mode_cmd.height = sizes->surface_height * fbdev_num_buffers; > mode_cmd.pitches[0] = sizes->surface_width * bytes_per_pixel; > mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp, > sizes->surface_depth); -- Regards, Laurent Pinchart _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
