On Mon, Nov 16, 2015 at 04:05:42PM +0000, Rodrigo Vivi wrote: > Ok, so after trying it we saw that we really cannot trust on aux mutex.At > least not on all SKL/KBL > It worked in a KBL but failed on a SKL that I have here... > > So without aux mutex option we still need to get sink_crc more reliable and > I see only 2 quick ways here: > - This read wake > - Return -EBUSY to force the drm retries on message size = 0. > > Daniel, what do you believe?
It's still a mess. My opinion is still that we should move the hacks from read_wake into a more suitable place: a) either into drm_dp_dpcd_read in drm_dp_helper.c b) or into intel_dp_aux_transfer in intel_dp.c Option a) is the right one if this is a generic sink issue (and it seems to be the case, at least for edp panels). Option b) if it's an issue with our hw. Either way I think intel_dp_dpcd_read_wake should die. On a personal gut level I'd go with option a). Cheers, Daniel > > Please let me know witch way and if necessary I rebase the patch and > re-send. > > Thanks, > Rodrigo. > > > > > On Wed, Oct 21, 2015 at 8:27 PM Thulasimani, Sivakumar < > sivakumar.thulasim...@intel.com> wrote: > > > > > > > On 10/22/2015 1:44 AM, Damien Lespiau wrote: > > > On Thu, Oct 22, 2015 at 12:01:21AM +0530, Thulasimani, Sivakumar wrote: > > >> > > >> On 8/25/2015 2:50 AM, Vivi, Rodrigo wrote: > > >>> On Mon, 2015-08-24 at 19:54 +0000, Zanoni, Paulo R wrote: > > >>>> Em Qui, 2015-08-20 às 16:23 -0700, Rodrigo Vivi escreveu: > > >>>>> Let's use a native read with retry as suggested per spec to > > >>>>> fix Sink CRC on SKL when PSR is enabled. > > >>>>> > > >>>>> With PSR enabled panel is probably taking more time to wake > > >>>>> and dpcd read is faling. > > >>>> Does this commit actually fix any known problem with Sink CRC? Or is > > >>>> it > > >>>> just a try? It would be nice to have this clarified in the commit > > >>>> message. > > >>> It was just a try but that made sink crc working on my SKL when PSR is > > >>> enabled. nothing much to add... > > >> SKL has new register AUX_MUTEX which should be used when accessing dpcd > > >> on edp. just searched the nightly code and could not find it. it might > > be > > >> the reason > > >> for random dpcd failures reported in the other thread. > > > We had patches for that back in December 2013 :) > > > > > > The feedback from Art was: > > > > > > The non-software aux users are PSR/SRD and GTC. > > > Better leave out the mutex for now. Hardware is going to try do the > > > arbitration itself. I expect you will then need to increase any > > software > > > timeout you may have. > > > > > > Do you know if anything has changed since then? > > > > > Not sure, it is in the bspec sequence to use AUX hence forwarded. Art > > might be the > > right person to contact :). it might be due to some minor DPCD access > > issues we > > observed in BDW when PSR was enabled. > > > > regards, > > Sivakumar > > _______________________________________________ > > Intel-gfx mailing list > > Intel-gfx@lists.freedesktop.org > > http://lists.freedesktop.org/mailman/listinfo/intel-gfx > > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx
