On Mon, Sep 23, 2024 at 09:42:27AM GMT, Jan Kiszka wrote: > On 28.08.24 15:32, Tomi Valkeinen wrote: > > On 26/08/2024 22:35, Jan Kiszka wrote: > >> On 24.06.24 12:17, Dmitry Baryshkov wrote: > >>> On Mon, 24 Jun 2024 at 13:07, Alexander Stein > >>> <alexander.stein@xxxxxxxxxxxxxxx> wrote: > >>>> > >>>> Hi, > >>>> > >>>> Am Montag, 24. Juni 2024, 11:49:04 CEST schrieb Dmitry Baryshkov: > >>>>> On Mon, Jun 24, 2024 at 03:07:10PM GMT, Aradhya Bhatia wrote: > >>>>>> > >>>>>> > >>>>>> On 22/06/24 17:49, Dmitry Baryshkov wrote: > >>>>>>> On Sat, Jun 22, 2024 at 05:16:58PM GMT, Aradhya Bhatia wrote: > >>>>>>>> > >>>>>>>> > >>>>>>>> On 17-Jun-24 13:41, Dmitry Baryshkov wrote: > >>>>>>>>> On Mon, Jun 17, 2024 at 07:40:32AM GMT, Jan Kiszka wrote: > >>>>>>>>>> On 16.02.24 15:57, Marek Vasut wrote: > >>>>>>>>>>> On 2/16/24 10:10, Tomi Valkeinen wrote: > >>>>>>>>>>>> Ok. Does anyone have a worry that these patches make the > >>>>>>>>>>>> situation > >>>>>>>>>>>> worse for the DSI case than it was before? Afaics, if the > >>>>>>>>>>>> DSI lanes > >>>>>>>>>>>> are not set up early enough by the DSI host, the driver > >>>>>>>>>>>> would break > >>>>>>>>>>>> with and without these patches. > >>>>>>>>>>>> > >>>>>>>>>>>> These do fix the driver for DRM_BRIDGE_ATTACH_NO_CONNECTOR > >>>>>>>>>>>> and DPI, so > >>>>>>>>>>>> I'd like to merge these unless these cause a regression with > >>>>>>>>>>>> the DSI > >>>>>>>>>>>> case. > >>>>>>>>>>> > >>>>>>>>>>> 1/2 looks good to me, go ahead and apply . > >>>>>>>> > >>>>>>>> Isn't there any way for the second patch to move forward as well > >>>>>>>> though? > >>>>>>>> The bridge device (under DPI to (e)DP mode) cannot really work > >>>>>>>> without > >>>>>>>> it, and the patches have been pending idle for a long time. =) > >>>>>>>> > >>>>>>>>>> > >>>>>>>>>> My local patches still apply on top of 6.10-rc4, so I don't > >>>>>>>>>> think this > >>>>>>>>>> ever happened. What's still holding up this long-pending fix > >>>>>>>>>> (at least > >>>>>>>>>> for our devices)? > >>>>>>>>> > >>>>>>>>> Neither of the patches contains Fixes tags. If the first patch > >>>>>>>>> fixes an > >>>>>>>>> issue in previous kernels, please consider following the stable > >>>>>>>>> process. > >>>>>>>>> > >>>>>>>>> If we are unsure about the second patch, please send the first > >>>>>>>>> patch > >>>>>>>>> separately, adding proper tags. > >>>>>>>>> > >>>>>>>> > >>>>>>>> Thanks Dmitry! I can send the patches again with the required fixes > >>>>>>>> tags (or just patch-1 if we cannot do anything about patch-2). > >>>>>>> > >>>>>>> The problem with the second patch is that it get mixed reviews. I > >>>>>>> can > >>>>>>> ack the first patch, but for the second one I'd need a > >>>>>>> confirmation from > >>>>>>> somebody else. I'll go on and apply the first patch later today. > >>>>>>> > >>>>>> > >>>>>> Thanks Dmitry! > >>>>>> > >>>>>> However, would it be okay if I instead add another patch that makes 2 > >>>>>> versions of the "tc_edp_bridge_funcs", say > >>>>>> "tc_dpi_edp_bridge_funcs" and > >>>>>> "tc_dsi_edp_bridge_funcs", that have all the same function hooks > >>>>>> except > >>>>>> for the .edid_read()? > >>>>>> > >>>>>> The dsi edid_read() will remain the same, and Tomi's patch - patch > >>>>>> 2/2 - > >>>>>> will only fix the dpi version of the edid_read()? > >>>>>> > >>>>>> The bridge already has the capability to distinguish a DSI input > >>>>>> from a > >>>>>> DPI input. This can be leveraged to decide which set of functions > >>>>>> need > >>>>>> to be used without any major changes. > >>>>> > >>>>> I'd prefer if somebody with the DSI setup can ack / test the second > >>>>> patch. > >>>>> > >>>>> > >>>> > >>>> Now that my DSI-DP setup works apparently without issue I could test > >>>> patch 2. > >>>> Since my setup does not use DRM_BRIDGE_ATTACH_NO_CONNECTOR (running on > >>>> drivers/gpu/drm/mxsfb/lcdif_drv.c), I can only say > >>>> there is no regression. > >>> > >>> Let me send a (non-tested) patch, switching to drm_bridge_connector, > >>> then you can probably test both of them > >>> > >> > >> I suppose [1] was that follow-up, just not leading to success, right? > >> > >> Now, what's next? I'd love to see the regression we have for the IOT2050 > >> devices finally fixed, even if it now only requires a short downstream > >> patch. > >> > >> Jan > >> > >> [1] > >> https://lore.kernel.org/dri-devel/20240624-mxc-lcdif-bridge-attach-v1-1-37e8c5d5d934@xxxxxxxxxx/ > > > > I have to say I don't remember the details for this anymore, but half a > > year ago I said: > > > >> Afaics, if the DSI lanes are not set up early enough by the DSI host, > >> the driver would break with and without these patches. > > > > I'm not sure if that is correct or not. But if it is, then, afaiu, this > > (the second patch): > > > > - Fixes the issue for the DPI-DP use case > > > > - Doesn't cause issues for the DSI-DP use case without > > DRM_BRIDGE_ATTACH_NO_CONNECTOR (as per Alexander's test) > > > > - Shouldn't cause (new) issues for the DSI-DP use case with > > DRM_BRIDGE_ATTACH_NO_CONNECTOR (as per my code review and guessing...) > > > > The third point is somewhat concerning, of course, but do we have any > > setup with DSI-DP and DRM_BRIDGE_ATTACH_NO_CONNECTOR that works now? If > > not, maybe we can just ignore the possible issues, as this fixes > > problems on a setup we do have. > > > > As Dmitry asked me during Plumbers to revalidate if our setup still > needs patch 2, I just did that over 6.11.0-next-20240923 (where patch 1 > is now included). No surprise, it is still needed for our iot2050 device > series, otherwise the display remains black. Granted that nobody with the DRM_BRIDGE_ATTACH_NO_CONNECTOR + DSI-DP spoke in the last several months, I think we'd better merge the patch as it is now. If noone objects (last call), I'll do that in one or two days. -- With best wishes Dmitry
