On Monday 14 April 2014 04:00 PM, Tomi Valkeinen wrote: > On 14/04/14 13:18, Archit Taneja wrote: >> On Monday 14 April 2014 02:55 PM, Tomi Valkeinen wrote: >>> On 11/04/14 10:23, Archit Taneja wrote: >>>> The drm ioctl DRM_IOCTL_MODE_ADDFB2 doesn't let us allocate buffers >>>> which are >>>> greater than what is specified in the driver through dev->mode_config. >>>> >>>> Create helpers for DISPC which return the max manager width and >>>> height supported >>>> by the device. The maximum width for a framebuffer is set to the >>>> combined width >>>> of the all the crtcs, assuming they are arranged horizontally. >>>> >>>> Signed-off-by: Archit Taneja <archit at ti.com> >>>> --- >>>> drivers/gpu/drm/omapdrm/omap_drv.c | 10 ++++++---- >>>> drivers/video/omap2/dss/dispc.c | 12 ++++++++++++ >>>> include/video/omapdss.h | 2 ++ >>>> 3 files changed, 20 insertions(+), 4 deletions(-) >>>> >>>> diff --git a/drivers/gpu/drm/omapdrm/omap_drv.c >>>> b/drivers/gpu/drm/omapdrm/omap_drv.c >>>> index c8270e4..55ec575 100644 >>>> --- a/drivers/gpu/drm/omapdrm/omap_drv.c >>>> +++ b/drivers/gpu/drm/omapdrm/omap_drv.c >>>> @@ -306,11 +306,13 @@ static int omap_modeset_init(struct drm_device >>>> *dev) >>>> dev->mode_config.min_width = 32; >>>> dev->mode_config.min_height = 32; >>>> >>>> - /* note: eventually will need some cpu_is_omapXYZ() type stuff here >>>> - * to fill in these limits properly on different OMAP generations.. >>>> + /* >>>> + * Note: the maximum width is set to the combined width of all the >>>> + * crtcs. We could assume the same for the maximum height too, but >>>> + * we generally don't use such a configuration. >>>> */ >>>> - dev->mode_config.max_width = 2048; >>>> - dev->mode_config.max_height = 2048; >>>> + dev->mode_config.max_width = num_crtcs * dispc_mgr_max_width(); >>>> + dev->mode_config.max_height = dispc_mgr_max_height(); >>> >>> This looks very strange. >>> >>> If the max size is supposed to be the maximum output size we support, >>> then multiplying with num_crtcs doesn't make sense. >>> >>> If, on the other hand, it tells the possible maximum size of the >>> framebuffer in the memory, of which only small part is shown (where's >>> the max size of that "part" defined, then?), then there should be no >>> limits as the only limit is the size of the memory. >> >> These parameters are used to tell the max size of framebuffer we can >> allocate in memory. >> >> I'm not sure why there is a limit in the first place, but if we have a >> really low minimum(like 2048 pixels right now), we can't have multiple >> displays showing different regions of the same buffer. > > In that case shouldn't the limit be 0 (if that's allowed) or some surely > high enough value, say, 32767. Why calculate it at all based on the > dispc's maximum, if it has no relevance?
I understand your point. When I wrote the patch, I thought more like: "I have 3 displays arranged horizontally, if I want a buffer large enough to fill the 3 displays, what should be it's width/height?" Archit
