Commit cccf4e3f authored Oct 09, 2017 by Jani Nikula

drm/dp: WARN about invalid/unknown link rates and bw codes



Falling back to the lowest value is likely the only thing we can do, but
doing it silently seems like a bad thing to do. Catch it early and make
loud noises.

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171009092959.29021-1-jani.nikula@intel.com

parent 7c0f24a4

drivers/gpu/drm/drm_dp_helper.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -137,8 +137,10 @@ EXPORT_SYMBOL(drm_dp_link_train_channel_eq_delay);
		u8 drm_dp_link_rate_to_bw_code(int link_rate)
		{
		switch (link_rate) {
		case 162000:
		default:
		WARN(1, "unknown DP link rate %d, using %x\n", link_rate,
		DP_LINK_BW_1_62);
		case 162000:
		return DP_LINK_BW_1_62;
		case 270000:
		return DP_LINK_BW_2_7;
		@@ -151,8 +153,9 @@ EXPORT_SYMBOL(drm_dp_link_rate_to_bw_code);
		int drm_dp_bw_code_to_link_rate(u8 link_bw)
		{
		switch (link_bw) {
		case DP_LINK_BW_1_62:
		default:
		WARN(1, "unknown DP link BW code %x, using 162000\n", link_bw);
		case DP_LINK_BW_1_62:
		return 162000;
		case DP_LINK_BW_2_7:
		return 270000;