4.4-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 092c96a8ab9d1bd60ada2ed385cc364ce084180e ] Need to properly handle the max link rate in the dpcd. This prevents some cases where 5.4 Ghz is selected when it shouldn't be. v2: simplify logic, add array bounds check Reviewed-by: Tom St Denis <tom.stdenis@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/radeon/atombios_dp.c | 108 +++++++++++---------------------- drivers/gpu/drm/radeon/radeon_dp_mst.c | 12 ++- drivers/gpu/drm/radeon/radeon_mode.h | 6 + 3 files changed, 49 insertions(+), 77 deletions(-) --- a/drivers/gpu/drm/radeon/atombios_dp.c +++ b/drivers/gpu/drm/radeon/atombios_dp.c @@ -302,77 +302,31 @@ static int convert_bpc_to_bpp(int bpc) return bpc * 3; } -/* get the max pix clock supported by the link rate and lane num */ -static int dp_get_max_dp_pix_clock(int link_rate, - int lane_num, - int bpp) -{ - return (link_rate * lane_num * 8) / bpp; -} - /***** radeon specific DP functions *****/ -int radeon_dp_get_max_link_rate(struct drm_connector *connector, - const u8 dpcd[DP_DPCD_SIZE]) -{ - int max_link_rate; - - if (radeon_connector_is_dp12_capable(connector)) - max_link_rate = min(drm_dp_max_link_rate(dpcd), 540000); - else - max_link_rate = min(drm_dp_max_link_rate(dpcd), 270000); - - return max_link_rate; -} - -/* First get the min lane# when low rate is used according to pixel clock - * (prefer low rate), second check max lane# supported by DP panel, - * if the max lane# < low rate lane# then use max lane# instead. - */ -static int radeon_dp_get_dp_lane_number(struct drm_connector *connector, - const u8 dpcd[DP_DPCD_SIZE], - int pix_clock) +int radeon_dp_get_dp_link_config(struct drm_connector *connector, + const u8 dpcd[DP_DPCD_SIZE], + unsigned pix_clock, + unsigned *dp_lanes, unsigned *dp_rate) { int bpp = convert_bpc_to_bpp(radeon_get_monitor_bpc(connector)); - int max_link_rate = radeon_dp_get_max_link_rate(connector, dpcd); - int max_lane_num = drm_dp_max_lane_count(dpcd); - int lane_num; - int max_dp_pix_clock; - - for (lane_num = 1; lane_num < max_lane_num; lane_num <<= 1) { - max_dp_pix_clock = dp_get_max_dp_pix_clock(max_link_rate, lane_num, bpp); - if (pix_clock <= max_dp_pix_clock) - break; - } - - return lane_num; -} - -static int radeon_dp_get_dp_link_clock(struct drm_connector *connector, - const u8 dpcd[DP_DPCD_SIZE], - int pix_clock) -{ - int bpp = convert_bpc_to_bpp(radeon_get_monitor_bpc(connector)); - int lane_num, max_pix_clock; - - if (radeon_connector_encoder_get_dp_bridge_encoder_id(connector) == - ENCODER_OBJECT_ID_NUTMEG) - return 270000; - - lane_num = radeon_dp_get_dp_lane_number(connector, dpcd, pix_clock); - max_pix_clock = dp_get_max_dp_pix_clock(162000, lane_num, bpp); - if (pix_clock <= max_pix_clock) - return 162000; - max_pix_clock = dp_get_max_dp_pix_clock(270000, lane_num, bpp); - if (pix_clock <= max_pix_clock) - return 270000; - if (radeon_connector_is_dp12_capable(connector)) { - max_pix_clock = dp_get_max_dp_pix_clock(540000, lane_num, bpp); - if (pix_clock <= max_pix_clock) - return 540000; + static const unsigned link_rates[3] = { 162000, 270000, 540000 }; + unsigned max_link_rate = drm_dp_max_link_rate(dpcd); + unsigned max_lane_num = drm_dp_max_lane_count(dpcd); + unsigned lane_num, i, max_pix_clock; + + for (lane_num = 1; lane_num <= max_lane_num; lane_num <<= 1) { + for (i = 0; i < ARRAY_SIZE(link_rates) && link_rates[i] <= max_link_rate; i++) { + max_pix_clock = (lane_num * link_rates[i] * 8) / bpp; + if (max_pix_clock >= pix_clock) { + *dp_lanes = lane_num; + *dp_rate = link_rates[i]; + return 0; + } + } } - return radeon_dp_get_max_link_rate(connector, dpcd); + return -EINVAL; } static u8 radeon_dp_encoder_service(struct radeon_device *rdev, @@ -491,6 +445,7 @@ void radeon_dp_set_link_config(struct dr { struct radeon_connector *radeon_connector = to_radeon_connector(connector); struct radeon_connector_atom_dig *dig_connector; + int ret; if (!radeon_connector->con_priv) return; @@ -498,10 +453,14 @@ void radeon_dp_set_link_config(struct dr if ((dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_DISPLAYPORT) || (dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_eDP)) { - dig_connector->dp_clock = - radeon_dp_get_dp_link_clock(connector, dig_connector->dpcd, mode->clock); - dig_connector->dp_lane_count = - radeon_dp_get_dp_lane_number(connector, dig_connector->dpcd, mode->clock); + ret = radeon_dp_get_dp_link_config(connector, dig_connector->dpcd, + mode->clock, + &dig_connector->dp_lane_count, + &dig_connector->dp_clock); + if (ret) { + dig_connector->dp_clock = 0; + dig_connector->dp_lane_count = 0; + } } } @@ -510,7 +469,8 @@ int radeon_dp_mode_valid_helper(struct d { struct radeon_connector *radeon_connector = to_radeon_connector(connector); struct radeon_connector_atom_dig *dig_connector; - int dp_clock; + unsigned dp_clock, dp_lanes; + int ret; if ((mode->clock > 340000) && (!radeon_connector_is_dp12_capable(connector))) @@ -520,8 +480,12 @@ int radeon_dp_mode_valid_helper(struct d return MODE_CLOCK_HIGH; dig_connector = radeon_connector->con_priv; - dp_clock = - radeon_dp_get_dp_link_clock(connector, dig_connector->dpcd, mode->clock); + ret = radeon_dp_get_dp_link_config(connector, dig_connector->dpcd, + mode->clock, + &dp_lanes, + &dp_clock); + if (ret) + return MODE_CLOCK_HIGH; if ((dp_clock == 540000) && (!radeon_connector_is_dp12_capable(connector))) --- a/drivers/gpu/drm/radeon/radeon_dp_mst.c +++ b/drivers/gpu/drm/radeon/radeon_dp_mst.c @@ -525,11 +525,17 @@ static bool radeon_mst_mode_fixup(struct drm_mode_set_crtcinfo(adjusted_mode, 0); { struct radeon_connector_atom_dig *dig_connector; + int ret; dig_connector = mst_enc->connector->con_priv; - dig_connector->dp_lane_count = drm_dp_max_lane_count(dig_connector->dpcd); - dig_connector->dp_clock = radeon_dp_get_max_link_rate(&mst_enc->connector->base, - dig_connector->dpcd); + ret = radeon_dp_get_dp_link_config(&mst_enc->connector->base, + dig_connector->dpcd, adjusted_mode->clock, + &dig_connector->dp_lane_count, + &dig_connector->dp_clock); + if (ret) { + dig_connector->dp_lane_count = 0; + dig_connector->dp_clock = 0; + } DRM_DEBUG_KMS("dig clock %p %d %d\n", dig_connector, dig_connector->dp_lane_count, dig_connector->dp_clock); } --- a/drivers/gpu/drm/radeon/radeon_mode.h +++ b/drivers/gpu/drm/radeon/radeon_mode.h @@ -757,8 +757,10 @@ extern u8 radeon_dp_getsinktype(struct r extern bool radeon_dp_getdpcd(struct radeon_connector *radeon_connector); extern int radeon_dp_get_panel_mode(struct drm_encoder *encoder, struct drm_connector *connector); -int radeon_dp_get_max_link_rate(struct drm_connector *connector, - const u8 *dpcd); +extern int radeon_dp_get_dp_link_config(struct drm_connector *connector, + const u8 *dpcd, + unsigned pix_clock, + unsigned *dp_lanes, unsigned *dp_rate); extern void radeon_dp_set_rx_power_state(struct drm_connector *connector, u8 power_state); extern void radeon_dp_aux_init(struct radeon_connector *radeon_connector); -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html