Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider: - [High] Checking `dp_128b_132b_supported_link_rates.raw` before it is read from the DPCD register completely disables DP 2.0 UHBR support. --
commit 11d06153280ec5dae6682a402606818b4f84b79d Author: Jackie Dong <[email protected]> drm/amd/display:Check dp_128b_132b_supported_link_rates.raw before link_rate setting This patch modifies the DP 128b/132b capability check to also verify that dp_128b_132b_supported_link_rates.raw is non-zero before attempting to read and parse the specific UHBR link rates. > diff --git > a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c > b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c > --- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c > +++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c > @@ -2079,7 +2079,8 @@ static bool retrieve_link_cap(struct dc_link *link) > if (!dpcd_read_sink_ext_caps(link)) > link->dpcd_sink_ext_caps.raw = 0; > > - if (link->dpcd_caps.channel_coding_cap.bits.DP_128b_132b_SUPPORTED) { > + if (link->dpcd_caps.channel_coding_cap.bits.DP_128b_132b_SUPPORTED && > + link->dpcd_caps.dp_128b_132b_supported_link_rates.raw) { [Severity: High] Will this change completely disable DP 2.0 UHBR support? In retrieve_link_cap() in drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c, dp_128b_132b_supported_link_rates.raw is now checked before it is actually read from the DPCD register. Since the dc_link struct is zero-initialized and the read hasn't occurred yet, won't this raw value always evaluate to 0 upon connection of any DP 2.0 monitor? This would cause the if condition to always fail, bypassing the actual read block below and permanently preventing UHBR feature detection. > DC_LOG_DP2("128b/132b encoding is supported at link %d", > link->link_index); > > /* Read 128b/132b suppoerted link rates */ > core_link_read_dpcd(link, > DP_128B132B_SUPPORTED_LINK_RATES, > > &link->dpcd_caps.dp_128b_132b_supported_link_rates.raw, -- Sashiko AI review ยท https://sashiko.dev/#/patchset/[email protected]?part=1
