[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: kevin@holm.dev kevin@holm.dev Sent: Monday, July 29, 2024 9:22 PM To: Linux regressions mailing list regressions@lists.linux.dev; Christian Heusel christian@heusel.eu Cc: Greg KH gregkh@linuxfoundation.org; Lin, Wayne Wayne.Lin@amd.com; stable@vger.kernel.org; LKML <linux- kernel@vger.kernel.org>; ML dri-devel dri-devel@lists.freedesktop.org; amd-gfx@lists.freedesktop.org; Wu, Hersen hersenxs.wu@amd.com; Deucher, Alexander Alexander.Deucher@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)" regressions@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 kevin@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