| Message ID | 20230823115425.715644-2-ankit.k.nautiyal@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | eDP DSC fixes | expand |
Hi Ankit, kernel test robot noticed the following build warnings: [auto build test WARNING on drm-tip/drm-tip] [also build test WARNING on linus/master v6.5-rc7 next-20230823] [cannot apply to drm-intel/for-linux-next drm-intel/for-linux-next-fixes drm-misc/drm-misc-next] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Ankit-Nautiyal/drm-display-dp-Default-8-bpc-support-when-DSC-is-supported/20230823-195946 base: git://anongit.freedesktop.org/drm/drm-tip drm-tip patch link: https://lore.kernel.org/r/20230823115425.715644-2-ankit.k.nautiyal%40intel.com patch subject: [PATCH 1/2] drm/display/dp: Default 8 bpc support when DSC is supported config: i386-randconfig-r036-20230823 (https://download.01.org/0day-ci/archive/20230824/202308240007.1edS9XsL-lkp@intel.com/config) compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07) reproduce: (https://download.01.org/0day-ci/archive/20230824/202308240007.1edS9XsL-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202308240007.1edS9XsL-lkp@intel.com/ All warnings (new ones prefixed by >>): >> drivers/gpu/drm/display/drm_dp_helper.c:2451:6: warning: logical not is only applied to the left hand side of this bitwise operator [-Wlogical-not-parentheses] if (!dsc_dpcd[DP_DSC_SUPPORT] & DP_DSC_DECOMPRESSION_IS_SUPPORTED) ^ ~ drivers/gpu/drm/display/drm_dp_helper.c:2451:6: note: add parentheses after the '!' to evaluate the bitwise operator first if (!dsc_dpcd[DP_DSC_SUPPORT] & DP_DSC_DECOMPRESSION_IS_SUPPORTED) ^ ( ) drivers/gpu/drm/display/drm_dp_helper.c:2451:6: note: add parentheses around left hand side expression to silence this warning if (!dsc_dpcd[DP_DSC_SUPPORT] & DP_DSC_DECOMPRESSION_IS_SUPPORTED) ^ ( ) 1 warning generated. vim +2451 drivers/gpu/drm/display/drm_dp_helper.c 2428 2429 /** 2430 * drm_dp_dsc_sink_supported_input_bpcs() - Get all the input bits per component 2431 * values supported by the DSC sink. 2432 * @dsc_dpcd: DSC capabilities from DPCD 2433 * @dsc_bpc: An array to be filled by this helper with supported 2434 * input bpcs. 2435 * 2436 * Read the DSC DPCD from the sink device to parse the supported bits per 2437 * component values. This is used to populate the DSC parameters 2438 * in the &struct drm_dsc_config by the driver. 2439 * Driver creates an infoframe using these parameters to populate 2440 * &struct drm_dsc_pps_infoframe. These are sent to the sink using DSC 2441 * infoframe using the helper function drm_dsc_pps_infoframe_pack() 2442 * 2443 * Returns: 2444 * Number of input BPC values parsed from the DPCD 2445 */ 2446 int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE], 2447 u8 dsc_bpc[3]) 2448 { 2449 int num_bpc = 0; 2450 > 2451 if (!dsc_dpcd[DP_DSC_SUPPORT] & DP_DSC_DECOMPRESSION_IS_SUPPORTED) 2452 return 0; 2453 2454 u8 color_depth = dsc_dpcd[DP_DSC_DEC_COLOR_DEPTH_CAP - DP_DSC_SUPPORT]; 2455 2456 if (color_depth & DP_DSC_12_BPC) 2457 dsc_bpc[num_bpc++] = 12; 2458 if (color_depth & DP_DSC_10_BPC) 2459 dsc_bpc[num_bpc++] = 10; 2460 2461 /* A DP DSC Sink devices shall support 8 bpc. */ 2462 dsc_bpc[num_bpc++] = 8; 2463 2464 return num_bpc; 2465 } 2466 EXPORT_SYMBOL(drm_dp_dsc_sink_supported_input_bpcs); 2467
diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c index e6a78fd32380..0aa4ce17420c 100644 --- a/drivers/gpu/drm/display/drm_dp_helper.c +++ b/drivers/gpu/drm/display/drm_dp_helper.c @@ -2447,14 +2447,19 @@ int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_S u8 dsc_bpc[3]) { int num_bpc = 0; + + if (!dsc_dpcd[DP_DSC_SUPPORT] & DP_DSC_DECOMPRESSION_IS_SUPPORTED) + return 0; + u8 color_depth = dsc_dpcd[DP_DSC_DEC_COLOR_DEPTH_CAP - DP_DSC_SUPPORT]; if (color_depth & DP_DSC_12_BPC) dsc_bpc[num_bpc++] = 12; if (color_depth & DP_DSC_10_BPC) dsc_bpc[num_bpc++] = 10; - if (color_depth & DP_DSC_8_BPC) - dsc_bpc[num_bpc++] = 8; + + /* A DP DSC Sink devices shall support 8 bpc. */ + dsc_bpc[num_bpc++] = 8; return num_bpc; }
As per DP v1.4, a DP DSC Sink device shall support 8bpc in DPCD 6Ah. Apparently some panels that do support DSC, are not setting the bit for 8bpc. So always assume 8bpc support by DSC decoder, when DSC is claimed to be supported. Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com> --- drivers/gpu/drm/display/drm_dp_helper.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)