diff options
author | Wesley Chalmers <Wesley.Chalmers@amd.com> | 2021-04-08 22:51:11 +0300 |
---|---|---|
committer | Alex Deucher <alexander.deucher@amd.com> | 2021-06-16 00:25:41 +0300 |
commit | 9cf9498f668d4c78616ebd2fe2e5f3850b189c5b (patch) | |
tree | 07cf48ff664841732dd03c86c3cf95958cf3375e | |
parent | 95ad72f4ade3db645279dae3bf4ed456ac806a1c (diff) | |
download | linux-9cf9498f668d4c78616ebd2fe2e5f3850b189c5b.tar.xz |
drm/amd/display: Partition DPCD address space and break up transactions
[WHY]
SCR for DP 2.0 spec says that multiple LTTPRs must not be accessed in a
single AUX transaction.
There may be other places in future where breaking up AUX accesses is
necessary.
[HOW]
Partition the entire DPCD address space into blocks. When an incoming AUX
request spans multiple blocks, break up the request into multiple requests.
Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
-rw-r--r-- | drivers/gpu/drm/amd/display/dc/core/dc_link_dpcd.c | 87 | ||||
-rw-r--r-- | include/drm/drm_dp_helper.h | 17 |
2 files changed, 102 insertions, 2 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dpcd.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dpcd.c index 8957565f87bc..27ec1e6e9c43 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dpcd.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dpcd.c @@ -44,6 +44,60 @@ static enum dc_status internal_link_write_dpcd( } /* + * Partition the entire DPCD address space + * XXX: This partitioning must cover the entire DPCD address space, + * and must contain no gaps or overlapping address ranges. + */ +static const struct dpcd_address_range mandatory_dpcd_partitions[] = { + { 0, DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR1) - 1}, + { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR1), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR2) - 1 }, + { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR2), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR3) - 1 }, + { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR3), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR4) - 1 }, + { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR4), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR5) - 1 }, + { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR5), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR6) - 1 }, + { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR6), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR7) - 1 }, + { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR7), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR8) - 1 }, + { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR8), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR1) - 1 }, + /* + * The FEC registers are contiguous + */ + { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR1), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR1) - 1 }, + { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR2), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR2) - 1 }, + { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR3), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR3) - 1 }, + { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR4), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR4) - 1 }, + { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR5), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR5) - 1 }, + { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR6), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR6) - 1 }, + { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR7), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR7) - 1 }, + { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR8), DP_LTTPR_MAX_ADD }, + /* all remaining DPCD addresses */ + { DP_LTTPR_MAX_ADD + 1, DP_DPCD_MAX_ADD } }; + +static inline bool do_addresses_intersect_with_range( + const struct dpcd_address_range *range, + const uint32_t start_address, + const uint32_t end_address) +{ + return start_address <= range->end && end_address >= range->start; +} + +static uint32_t dpcd_get_next_partition_size(const uint32_t address, const uint32_t size) +{ + const uint32_t end_address = END_ADDRESS(address, size); + uint32_t partition_iterator = 0; + + /* + * find current partition + * this loop spins forever if partition map above is not surjective + */ + while (!do_addresses_intersect_with_range(&mandatory_dpcd_partitions[partition_iterator], + address, end_address)) + partition_iterator++; + if (end_address < mandatory_dpcd_partitions[partition_iterator].end) + return size; + return ADDRESS_RANGE_SIZE(address, mandatory_dpcd_partitions[partition_iterator].end); +} + +/* * Ranges of DPCD addresses that must be read in a single transaction * XXX: Do not allow any two address ranges in this array to overlap */ @@ -115,12 +169,28 @@ enum dc_status core_link_read_dpcd( uint32_t size) { uint32_t extended_address; + uint32_t partitioned_address; uint8_t *extended_data; uint32_t extended_size; + /* size of the remaining partitioned address space */ + uint32_t size_left_to_read; enum dc_status status; + /* size of the next partition to be read from */ + uint32_t partition_size; + uint32_t data_index = 0; dpcd_extend_address_range(address, data, size, &extended_address, &extended_data, &extended_size); - status = internal_link_read_dpcd(link, extended_address, extended_data, extended_size); + partitioned_address = extended_address; + size_left_to_read = extended_size; + while (size_left_to_read) { + partition_size = dpcd_get_next_partition_size(partitioned_address, size_left_to_read); + status = internal_link_read_dpcd(link, partitioned_address, &extended_data[data_index], partition_size); + if (status != DC_OK) + break; + partitioned_address += partition_size; + data_index += partition_size; + size_left_to_read -= partition_size; + } dpcd_reduce_address_range(extended_address, extended_data, extended_size, address, data, size); return status; } @@ -131,5 +201,18 @@ enum dc_status core_link_write_dpcd( const uint8_t *data, uint32_t size) { - return internal_link_write_dpcd(link, address, data, size); + uint32_t partition_size; + uint32_t data_index = 0; + enum dc_status status; + + while (size) { + partition_size = dpcd_get_next_partition_size(address, size); + status = internal_link_write_dpcd(link, address, &data[data_index], partition_size); + if (status != DC_OK) + break; + address += partition_size; + data_index += partition_size; + size -= partition_size; + } + return status; } diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index 06681bf46d81..3f2715eb965f 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -1377,10 +1377,27 @@ enum drm_dp_phy { #define DP_SYMBOL_ERROR_COUNT_LANE1_PHY_REPEATER1 0xf0037 /* 1.3 */ #define DP_SYMBOL_ERROR_COUNT_LANE2_PHY_REPEATER1 0xf0039 /* 1.3 */ #define DP_SYMBOL_ERROR_COUNT_LANE3_PHY_REPEATER1 0xf003b /* 1.3 */ + +#define __DP_FEC1_BASE 0xf0290 /* 1.4 */ +#define __DP_FEC2_BASE 0xf0298 /* 1.4 */ +#define DP_FEC_BASE(dp_phy) \ + (__DP_FEC1_BASE + ((__DP_FEC2_BASE - __DP_FEC1_BASE) * \ + ((dp_phy) - DP_PHY_LTTPR1))) + +#define DP_FEC_REG(dp_phy, fec1_reg) \ + (DP_FEC_BASE(dp_phy) - DP_FEC_BASE(DP_PHY_LTTPR1) + fec1_reg) + #define DP_FEC_STATUS_PHY_REPEATER1 0xf0290 /* 1.4 */ +#define DP_FEC_STATUS_PHY_REPEATER(dp_phy) \ + DP_FEC_REG(dp_phy, DP_FEC_STATUS_PHY_REPEATER1) + #define DP_FEC_ERROR_COUNT_PHY_REPEATER1 0xf0291 /* 1.4 */ #define DP_FEC_CAPABILITY_PHY_REPEATER1 0xf0294 /* 1.4a */ +#define DP_LTTPR_MAX_ADD 0xf02ff /* 1.4 */ + +#define DP_DPCD_MAX_ADD 0xfffff /* 1.4 */ + /* Repeater modes */ #define DP_PHY_REPEATER_MODE_TRANSPARENT 0x55 /* 1.3 */ #define DP_PHY_REPEATER_MODE_NON_TRANSPARENT 0xaa /* 1.3 */ |