diff options
Diffstat (limited to 'drivers/gpu/drm/dp/drm_dp.c')
| -rw-r--r-- | drivers/gpu/drm/dp/drm_dp.c | 58 |
1 files changed, 36 insertions, 22 deletions
diff --git a/drivers/gpu/drm/dp/drm_dp.c b/drivers/gpu/drm/dp/drm_dp.c index 703972ae14c6..580016a1b9eb 100644 --- a/drivers/gpu/drm/dp/drm_dp.c +++ b/drivers/gpu/drm/dp/drm_dp.c @@ -2390,9 +2390,36 @@ int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_S } EXPORT_SYMBOL(drm_dp_dsc_sink_supported_input_bpcs); +static int drm_dp_read_lttpr_regs(struct drm_dp_aux *aux, + const u8 dpcd[DP_RECEIVER_CAP_SIZE], int address, + u8 *buf, int buf_size) +{ + /* + * At least the DELL P2715Q monitor with a DPCD_REV < 0x14 returns + * corrupted values when reading from the 0xF0000- range with a block + * size bigger than 1. + */ + int block_size = dpcd[DP_DPCD_REV] < 0x14 ? 1 : buf_size; + int offset; + int ret; + + for (offset = 0; offset < buf_size; offset += block_size) { + ret = drm_dp_dpcd_read(aux, + address + offset, + &buf[offset], block_size); + if (ret < 0) + return ret; + + WARN_ON(ret != block_size); + } + + return 0; +} + /** * drm_dp_read_lttpr_common_caps - read the LTTPR common capabilities * @aux: DisplayPort AUX channel + * @dpcd: DisplayPort configuration data * @caps: buffer to return the capability info in * * Read capabilities common to all LTTPRs. @@ -2400,25 +2427,19 @@ EXPORT_SYMBOL(drm_dp_dsc_sink_supported_input_bpcs); * Returns 0 on success or a negative error code on failure. */ int drm_dp_read_lttpr_common_caps(struct drm_dp_aux *aux, + const u8 dpcd[DP_RECEIVER_CAP_SIZE], u8 caps[DP_LTTPR_COMMON_CAP_SIZE]) { - int ret; - - ret = drm_dp_dpcd_read(aux, - DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV, - caps, DP_LTTPR_COMMON_CAP_SIZE); - if (ret < 0) - return ret; - - WARN_ON(ret != DP_LTTPR_COMMON_CAP_SIZE); - - return 0; + return drm_dp_read_lttpr_regs(aux, dpcd, + DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV, + caps, DP_LTTPR_COMMON_CAP_SIZE); } EXPORT_SYMBOL(drm_dp_read_lttpr_common_caps); /** * drm_dp_read_lttpr_phy_caps - read the capabilities for a given LTTPR PHY * @aux: DisplayPort AUX channel + * @dpcd: DisplayPort configuration data * @dp_phy: LTTPR PHY to read the capabilities for * @caps: buffer to return the capability info in * @@ -2427,20 +2448,13 @@ EXPORT_SYMBOL(drm_dp_read_lttpr_common_caps); * Returns 0 on success or a negative error code on failure. */ int drm_dp_read_lttpr_phy_caps(struct drm_dp_aux *aux, + const u8 dpcd[DP_RECEIVER_CAP_SIZE], enum drm_dp_phy dp_phy, u8 caps[DP_LTTPR_PHY_CAP_SIZE]) { - int ret; - - ret = drm_dp_dpcd_read(aux, - DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER(dp_phy), - caps, DP_LTTPR_PHY_CAP_SIZE); - if (ret < 0) - return ret; - - WARN_ON(ret != DP_LTTPR_PHY_CAP_SIZE); - - return 0; + return drm_dp_read_lttpr_regs(aux, dpcd, + DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER(dp_phy), + caps, DP_LTTPR_PHY_CAP_SIZE); } EXPORT_SYMBOL(drm_dp_read_lttpr_phy_caps); |