[Public] Thanks, Kevin. The revert patch seems correct, but we plan to refactor this function as the following patch fa57924c76d995 ("drm/amd/display: Refactor function dm_dp_mst_is_port_support_mode()")
I'll make time to provide one. Thanks! Regards, Wayne > -----Original Message----- > From: ke...@holm.dev <ke...@holm.dev> > Sent: Monday, July 29, 2024 9:22 PM > To: Linux regressions mailing list <regressi...@lists.linux.dev>; Christian > Heusel <christ...@heusel.eu> > Cc: Greg KH <gre...@linuxfoundation.org>; Lin, Wayne > <wayne....@amd.com>; sta...@vger.kernel.org; LKML <linux- > ker...@vger.kernel.org>; ML dri-devel <dri-de...@lists.freedesktop.org>; > amd-gfx@lists.freedesktop.org; Wu, Hersen <hersenxs...@amd.com>; > Deucher, Alexander <alexander.deuc...@amd.com> > Subject: Re: [REGRESSION] No image on 4k display port displays connected > through usb-c dock in kernel 6.10 > > July 29, 2024 at 11:15 AM, "Linux regression tracking (Thorsten Leemhuis)" > <regressi...@leemhuis.info> wrote: > > > > > > > On 29.07.24 10:47, Christian Heusel wrote: > > > > > > > > On 24/07/29 10:35AM, Linux regression tracking (Thorsten Leemhuis) > wrote: > > > > > > > > > > > [+Greg +stable] > > > > > > > > On 29.07.24 10:16, Lin, Wayne wrote: > > > > > > > > > > Thanks for the report. > > > > > > Patch fa57924c76d995 ("drm/amd/display: Refactor function > > > dm_dp_mst_is_port_support_mode()") > > > > > > is kind of correcting problems causing by commit: > > > > > > 4df96ba6676034 ("drm/amd/display: Add timing pixel encoding for mst > > > mode validation") > > > > > > Sorry if it misses fixes tag and would suggest to backport to fix it. > > > Thanks! > > > > > > > > > > > Greg, seem it would be wise to pick up fa57924c76d995 for 6.10.y > > > > as > > > > > > > > well, despite a lack of Fixes or stable tags. > > > > > > > > Ciao, Thorsten > > > > > > > > > > > > > > > > The issue is that the fixing commit does not apply to the 6.10 > > > series > > > > > > without conflict and the offending commit does not revert cleanly > > > > > > aswell. > > > > > > > Hah, many thx, I should have checked that. > > > > Lin, Wayne: could you maybe help out here and provide something for > 6.10.y? > > > > Ciao, Thorsten > > > > I reverted 4df96ba6676034 from v6.10.2 from the stable/linux git, resolving > the conflict by removing everything that git marked as from the current branch > and kept everything marked as from before the branch to merge. That resulted > in a patch that is fixing the problem on my machine. Since I don't understand > what the code is actually doing it might break things on other machines. > > From cd1674a469cede83f6b0907f320b6af08c3c8950 Mon Sep 17 00:00:00 > 2001 > From: Kevin Holm <ke...@holm.dev> > Date: Mon, 29 Jul 2024 13:24:38 +0200 > Subject: [PATCH] Test patch > > --- > .../display/amdgpu_dm/amdgpu_dm_mst_types.c | 33 +++---------------- > 1 file changed, 5 insertions(+), 28 deletions(-) > > diff --git > a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c > b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c > index a5e1a93ddaea..5c555a37e367 100644 > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c > @@ -1599,7 +1599,7 @@ enum dc_status > dm_dp_mst_is_port_support_mode( > struct amdgpu_dm_connector *aconnector, > struct dc_stream_state *stream) > { > - int pbn, branch_max_throughput_mps = 0; > + int bpp, pbn, branch_max_throughput_mps = 0; > struct dc_link_settings cur_link_settings; > unsigned int end_to_end_bw_in_kbps = 0; > unsigned int upper_link_bw_in_kbps = 0, down_link_bw_in_kbps = 0; @@ - > 1649,34 +1649,11 @@ enum dc_status dm_dp_mst_is_port_support_mode( > } > } > } else { > - /* Check if mode could be supported within max slot > - * number of current mst link and full_pbn of mst links. > - */ > - int pbn_div, slot_num, max_slot_num; > - enum dc_link_encoding_format link_encoding; > - uint32_t stream_kbps = > - dc_bandwidth_in_kbps_from_timing(&stream->timing, > - dc_link_get_highest_encoding_format(stream->link)); > - > - pbn = kbps_to_peak_pbn(stream_kbps); > - pbn_div = dm_mst_get_pbn_divider(stream->link); > - slot_num = DIV_ROUND_UP(pbn, pbn_div); > - > - link_encoding = dc_link_get_highest_encoding_format(stream->link); > - if (link_encoding == DC_LINK_ENCODING_DP_8b_10b) > - max_slot_num = 63; > - else if (link_encoding == DC_LINK_ENCODING_DP_128b_132b) > - max_slot_num = 64; > - else { > - DRM_DEBUG_DRIVER("Invalid link encoding format\n"); > + /* check if mode could be supported within full_pbn */ > + bpp = convert_dc_color_depth_into_bpc(stream- > >timing.display_color_depth) * 3; > + pbn = drm_dp_calc_pbn_mode(stream->timing.pix_clk_100hz / 10, bpp > << 4); > + if (pbn > aconnector->mst_output_port->full_pbn) > return DC_FAIL_BANDWIDTH_VALIDATE; > - } > - > - if (slot_num > max_slot_num || > - pbn > aconnector->mst_output_port->full_pbn) { > - DRM_DEBUG_DRIVER("Mode can not be supported within mst links!"); > - return DC_FAIL_BANDWIDTH_VALIDATE; > - } > } > > /* check is mst dsc output bandwidth branch_overall_throughput_0_mps > */ > -- > 2.45.2 > > > Regards, > Kevin