On Wed, Oct 14, 2015 at 10:20:32AM +0000, Shankar, Uma wrote: > > > >-----Original Message----- > >From: Daniel Vetter [mailto:daniel.vetter@xxxxxxxx] On Behalf Of Daniel Vetter > >Sent: Tuesday, October 13, 2015 9:17 PM > >To: Shankar, Uma > >Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx; Kumar, Shobhit > >Subject: Re: [BXT DSI timing fixes v1 3/3] drm/i915/bxt: Fixed dsi enc > >disable and blank at bootup > > > >On Mon, Oct 12, 2015 at 10:55:03PM +0530, Uma Shankar wrote: > >> During bootup, mipi display was blanking in BXT. This is because > >> during driver load, though encoder, connector were active but crtc > >> returned inactive. This caused sanitize function to disable the DSI > >> panel. In AOS, this is fine since HWC will do a modeset and crtc, > >> connector, encoder mapping will be restored. But in Charging OS, no > >> modeset is called, it just calls DPMS ON/OFF. Hence display doesn't > >> come in COS. This is needed even for seamless booting to Android without a > >blank. > >> > >> This is fine on BYT/CHT since transcoder is common b/w all encoders. > >> But for BXT, there is a separate mipi transcoder. Hence this needs > >> special handling for BXT DSI. > >> > >> Signed-off-by: Uma Shankar <uma.shankar@xxxxxxxxx> > >> --- > >> drivers/gpu/drm/i915/i915_drv.h | 3 +++ > >> drivers/gpu/drm/i915/intel_display.c | 27 +++++++++++++++++++++++---- > >> 2 files changed, 26 insertions(+), 4 deletions(-) > >> > >> diff --git a/drivers/gpu/drm/i915/i915_drv.h > >> b/drivers/gpu/drm/i915/i915_drv.h index bf14096..ae790ec 100644 > >> --- a/drivers/gpu/drm/i915/i915_drv.h > >> +++ b/drivers/gpu/drm/i915/i915_drv.h > >> @@ -1948,6 +1948,9 @@ struct drm_i915_private { > >> /* perform PHY state sanity checks? */ > >> bool chv_phy_assert[2]; > >> > >> + /* To check if DSI is initializing at bootup */ > >> + bool dsi_enumerating; > > > >See my other comment, you're working around the broken design of patch 2 > >here. Special casing fastboot is a big no-no which needs some really good > >reasons. An example is the special edp clock readout code in the encoder > >callbacks we have for ilk-ivb cpu edp. > >-Daniel > > > > I agree this is not a clean solution but was not getting any better > ideas. As part of driver load and initialization, readout_state returns > encoder, connector as active but all crtc return inactive. This make > sanitize encoder to consider this as inconsistent hw state and it goes > ahead and disables encoder, thereby disabling the BIOS/GOP > Initialization. > > After this only way to recover is a modeset which doesn't come in cases > like Charging OS in Android. Also this will create issues in having a > seamless boot without a blank (a must have for Android devices). > > For EDP case, we can read DDI_FUNC_CTL and get a pipe number and match > it with crtc->pipe to detect EDP is on that pipe and map it to crtc. > > In DSI there is no such mechanism to detect this. Can you suggest some > pointers as to how to approach this issue. MIPI_CTRL(port) has BXT_PIPE_SELECT_A/C bits. Which btw we don't ever seem to check anywhere in intel_dsi_compute_config, which is a pretty stellar bug that running kms_flip even once should have caught. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
