[PATCH 6.6 210/322] drm/amd/display: Fix minor issues in BW Allocation Phase2

6.6-stable review patch. If anyone has any objections, please let me know.

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From: Meenakshikumar Somasundaram meenakshikumar.somasundaram@amd.com

[ Upstream commit aa5dc05340eb97486a631ce6bccb8d020bf6b56b ]

[Why] Fix minor issues in BW Allocation Phase2.

[How] - In set_usb4_req_bw_req(), link->dpia_bw_alloc_config.response_ready flag should be reset before writing DPCD REQUEST_BW. - Fix the granularity for value of 2 in get_bw_granularity(). - Removed bandwidth allocation support display fw boot option as the fw would read feature enable status from bios. - Clean up DPIA_EST_BW_CHANGED and DPIA_BW_REQ_SUCCESS cases in dpia_handle_bw_alloc_response(). - Removed allocate_usb4_bw and deallocate_usb4_bw. - Optimized loop in get_lowest_dpia_index(). - Updated link_dp_dpia_allocate_usb4_bandwidth_for_stream() and set_usb4_req_bw_req() to always issue request bw.

Tested-by: Daniel Wheeler daniel.wheeler@amd.com Reviewed-by: PeiChen Huang peichen.huang@amd.com Acked-by: Rodrigo Siqueira rodrigo.siqueira@amd.com Signed-off-by: Meenakshikumar Somasundaram meenakshikumar.somasundaram@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- .../dc/link/protocols/link_dp_dpia_bw.c | 221 ++++++++---------- .../dc/link/protocols/link_dp_dpia_bw.h | 4 +- 2 files changed, 101 insertions(+), 124 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c index 7581023daa47..d6e1f969bfd5 100644 --- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c +++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c @@ -50,6 +50,7 @@ static bool get_bw_alloc_proceed_flag(struct dc_link *tmp) && tmp->hpd_status && tmp->dpia_bw_alloc_config.bw_alloc_enabled); } + static void reset_bw_alloc_struct(struct dc_link *link) { link->dpia_bw_alloc_config.bw_alloc_enabled = false; @@ -59,6 +60,11 @@ static void reset_bw_alloc_struct(struct dc_link *link) link->dpia_bw_alloc_config.bw_granularity = 0; link->dpia_bw_alloc_config.response_ready = false; } + +#define BW_GRANULARITY_0 4 // 0.25 Gbps +#define BW_GRANULARITY_1 2 // 0.5 Gbps +#define BW_GRANULARITY_2 1 // 1 Gbps + static uint8_t get_bw_granularity(struct dc_link *link) { uint8_t bw_granularity = 0; @@ -71,16 +77,20 @@ static uint8_t get_bw_granularity(struct dc_link *link)

switch (bw_granularity & 0x3) { case 0: - bw_granularity = 4; + bw_granularity = BW_GRANULARITY_0; break; case 1: + bw_granularity = BW_GRANULARITY_1; + break; + case 2: default: - bw_granularity = 2; + bw_granularity = BW_GRANULARITY_2; break; }

return bw_granularity; } + static int get_estimated_bw(struct dc_link *link) { uint8_t bw_estimated_bw = 0; @@ -93,31 +103,7 @@ static int get_estimated_bw(struct dc_link *link)

return bw_estimated_bw * (Kbps_TO_Gbps / link->dpia_bw_alloc_config.bw_granularity); } -static bool allocate_usb4_bw(int *stream_allocated_bw, int bw_needed, struct dc_link *link) -{ - if (bw_needed > 0) - *stream_allocated_bw += bw_needed; - - return true; -} -static bool deallocate_usb4_bw(int *stream_allocated_bw, int bw_to_dealloc, struct dc_link *link) -{ - bool ret = false; - - if (*stream_allocated_bw > 0) { - *stream_allocated_bw -= bw_to_dealloc; - ret = true; - } else { - //Do nothing for now - ret = true; - }

- // Unplug so reset values - if (!link->hpd_status) - reset_bw_alloc_struct(link); - - return ret; -} /* * Read all New BW alloc configuration ex: estimated_bw, allocated_bw, * granuality, Driver_ID, CM_Group, & populate the BW allocation structs @@ -128,7 +114,12 @@ static void init_usb4_bw_struct(struct dc_link *link) // Init the known values link->dpia_bw_alloc_config.bw_granularity = get_bw_granularity(link); link->dpia_bw_alloc_config.estimated_bw = get_estimated_bw(link); + + DC_LOG_DEBUG("%s: bw_granularity(%d), estimated_bw(%d)\n", + __func__, link->dpia_bw_alloc_config.bw_granularity, + link->dpia_bw_alloc_config.estimated_bw); } + static uint8_t get_lowest_dpia_index(struct dc_link *link) { const struct dc *dc_struct = link->dc; @@ -141,12 +132,15 @@ static uint8_t get_lowest_dpia_index(struct dc_link *link) dc_struct->links[i]->ep_type != DISPLAY_ENDPOINT_USB4_DPIA) continue;

- if (idx > dc_struct->links[i]->link_index) + if (idx > dc_struct->links[i]->link_index) { idx = dc_struct->links[i]->link_index; + break; + } }

return idx; } + /* * Get the Max Available BW or Max Estimated BW for each Host Router * @@ -186,6 +180,7 @@ static int get_host_router_total_bw(struct dc_link *link, uint8_t type)

return total_bw; } + /* * Cleanup function for when the dpia is unplugged to reset struct * and perform any required clean up @@ -194,42 +189,50 @@ static int get_host_router_total_bw(struct dc_link *link, uint8_t type) * * return: none */ -static bool dpia_bw_alloc_unplug(struct dc_link *link) +static void dpia_bw_alloc_unplug(struct dc_link *link) { - if (!link) - return true; - - return deallocate_usb4_bw(&link->dpia_bw_alloc_config.sink_allocated_bw, - link->dpia_bw_alloc_config.sink_allocated_bw, link); + if (link) { + DC_LOG_DEBUG("%s: resetting bw alloc config for link(%d)\n", + __func__, link->link_index); + link->dpia_bw_alloc_config.sink_allocated_bw = 0; + reset_bw_alloc_struct(link); + } } + static void set_usb4_req_bw_req(struct dc_link *link, int req_bw) { uint8_t requested_bw; uint32_t temp;

- // 1. Add check for this corner case #1 - if (req_bw > link->dpia_bw_alloc_config.estimated_bw) + /* Error check whether request bw greater than allocated */ + if (req_bw > link->dpia_bw_alloc_config.estimated_bw) { + DC_LOG_ERROR("%s: Request bw greater than estimated bw for link(%d)\n", + __func__, link->link_index); req_bw = link->dpia_bw_alloc_config.estimated_bw; + }

temp = req_bw * link->dpia_bw_alloc_config.bw_granularity; requested_bw = temp / Kbps_TO_Gbps;

- // Always make sure to add more to account for floating points + /* Always make sure to add more to account for floating points */ if (temp % Kbps_TO_Gbps) ++requested_bw;

- // 2. Add check for this corner case #2 + /* Error check whether requested and allocated are equal */ req_bw = requested_bw * (Kbps_TO_Gbps / link->dpia_bw_alloc_config.bw_granularity); - if (req_bw == link->dpia_bw_alloc_config.sink_allocated_bw) - return; + if (req_bw == link->dpia_bw_alloc_config.sink_allocated_bw) { + DC_LOG_ERROR("%s: Request bw equals to allocated bw for link(%d)\n", + __func__, link->link_index); + }

- if (core_link_write_dpcd( + link->dpia_bw_alloc_config.response_ready = false; // Reset flag + core_link_write_dpcd( link, REQUESTED_BW, &requested_bw, - sizeof(uint8_t)) == DC_OK) - link->dpia_bw_alloc_config.response_ready = false; // Reset flag + sizeof(uint8_t)); } + /* * Return the response_ready flag from dc_link struct * @@ -241,6 +244,7 @@ static bool get_cm_response_ready_flag(struct dc_link *link) { return link->dpia_bw_alloc_config.response_ready; } + // ------------------------------------------------------------------ // PUBLIC FUNCTIONS // ------------------------------------------------------------------ @@ -277,27 +281,27 @@ bool link_dp_dpia_set_dptx_usb4_bw_alloc_support(struct dc_link *link) DPTX_BW_ALLOCATION_MODE_CONTROL, &response, sizeof(uint8_t)) != DC_OK) { - DC_LOG_DEBUG("%s: **** FAILURE Enabling DPtx BW Allocation Mode Support ***\n", - __func__); + DC_LOG_DEBUG("%s: FAILURE Enabling DPtx BW Allocation Mode Support for link(%d)\n", + __func__, link->link_index); } else { // SUCCESS Enabled DPtx BW Allocation Mode Support - link->dpia_bw_alloc_config.bw_alloc_enabled = true; - DC_LOG_DEBUG("%s: **** SUCCESS Enabling DPtx BW Allocation Mode Support ***\n", - __func__); + DC_LOG_DEBUG("%s: SUCCESS Enabling DPtx BW Allocation Mode Support for link(%d)\n", + __func__, link->link_index);

ret = true; init_usb4_bw_struct(link); + link->dpia_bw_alloc_config.bw_alloc_enabled = true; } }

out: return ret; } + void dpia_handle_bw_alloc_response(struct dc_link *link, uint8_t bw, uint8_t result) { int bw_needed = 0; int estimated = 0; - int host_router_total_estimated_bw = 0;

if (!get_bw_alloc_proceed_flag((link))) return; @@ -306,14 +310,22 @@ void dpia_handle_bw_alloc_response(struct dc_link *link, uint8_t bw, uint8_t res

case DPIA_BW_REQ_FAILED:

- DC_LOG_DEBUG("%s: *** *** BW REQ FAILURE for DP-TX Request *** ***\n", __func__); + /* + * Ideally, we shouldn't run into this case as we always validate available + * bandwidth and request within that limit + */ + estimated = bw * (Kbps_TO_Gbps / link->dpia_bw_alloc_config.bw_granularity);

- // Update the new Estimated BW value updated by CM - link->dpia_bw_alloc_config.estimated_bw = - bw * (Kbps_TO_Gbps / link->dpia_bw_alloc_config.bw_granularity); + DC_LOG_ERROR("%s: BW REQ FAILURE for DP-TX Request for link(%d)\n", + __func__, link->link_index); + DC_LOG_ERROR("%s: current estimated_bw(%d), new estimated_bw(%d)\n", + __func__, link->dpia_bw_alloc_config.estimated_bw, estimated);

+ /* Update the new Estimated BW value updated by CM */ + link->dpia_bw_alloc_config.estimated_bw = estimated; + + /* Allocate the previously requested bandwidth */ set_usb4_req_bw_req(link, link->dpia_bw_alloc_config.estimated_bw); - link->dpia_bw_alloc_config.response_ready = false;

/* * If FAIL then it is either: @@ -326,68 +338,34 @@ void dpia_handle_bw_alloc_response(struct dc_link *link, uint8_t bw, uint8_t res

case DPIA_BW_REQ_SUCCESS:

- DC_LOG_DEBUG("%s: *** BW REQ SUCCESS for DP-TX Request ***\n", __func__); - - // 1. SUCCESS 1st time before any Pruning is done - // 2. SUCCESS after prev. FAIL before any Pruning is done - // 3. SUCCESS after Pruning is done but before enabling link - bw_needed = bw * (Kbps_TO_Gbps / link->dpia_bw_alloc_config.bw_granularity);

- // 1. - if (!link->dpia_bw_alloc_config.sink_allocated_bw) { - - allocate_usb4_bw(&link->dpia_bw_alloc_config.sink_allocated_bw, bw_needed, link); - link->dpia_bw_alloc_config.sink_verified_bw = - link->dpia_bw_alloc_config.sink_allocated_bw; + DC_LOG_DEBUG("%s: BW REQ SUCCESS for DP-TX Request for link(%d)\n", + __func__, link->link_index); + DC_LOG_DEBUG("%s: current allocated_bw(%d), new allocated_bw(%d)\n", + __func__, link->dpia_bw_alloc_config.sink_allocated_bw, bw_needed);

- // SUCCESS from first attempt - if (link->dpia_bw_alloc_config.sink_allocated_bw > - link->dpia_bw_alloc_config.sink_max_bw) - link->dpia_bw_alloc_config.sink_verified_bw = - link->dpia_bw_alloc_config.sink_max_bw; - } - // 3. - else if (link->dpia_bw_alloc_config.sink_allocated_bw) { - - // Find out how much do we need to de-alloc - if (link->dpia_bw_alloc_config.sink_allocated_bw > bw_needed) - deallocate_usb4_bw(&link->dpia_bw_alloc_config.sink_allocated_bw, - link->dpia_bw_alloc_config.sink_allocated_bw - bw_needed, link); - else - allocate_usb4_bw(&link->dpia_bw_alloc_config.sink_allocated_bw, - bw_needed - link->dpia_bw_alloc_config.sink_allocated_bw, link); - } - - // 4. If this is the 2nd sink then any unused bw will be reallocated to master DPIA - // => check if estimated_bw changed + link->dpia_bw_alloc_config.sink_allocated_bw = bw_needed;

link->dpia_bw_alloc_config.response_ready = true; break;

case DPIA_EST_BW_CHANGED:

- DC_LOG_DEBUG("%s: *** ESTIMATED BW CHANGED for DP-TX Request ***\n", __func__); - estimated = bw * (Kbps_TO_Gbps / link->dpia_bw_alloc_config.bw_granularity); - host_router_total_estimated_bw = get_host_router_total_bw(link, HOST_ROUTER_BW_ESTIMATED);

- // 1. If due to unplug of other sink - if (estimated == host_router_total_estimated_bw) { - // First update the estimated & max_bw fields - if (link->dpia_bw_alloc_config.estimated_bw < estimated) - link->dpia_bw_alloc_config.estimated_bw = estimated; - } - // 2. If due to realloc bw btw 2 dpia due to plug OR realloc unused Bw - else { - // We lost estimated bw usually due to plug event of other dpia - link->dpia_bw_alloc_config.estimated_bw = estimated; - } + DC_LOG_DEBUG("%s: ESTIMATED BW CHANGED for link(%d)\n", + __func__, link->link_index); + DC_LOG_DEBUG("%s: current estimated_bw(%d), new estimated_bw(%d)\n", + __func__, link->dpia_bw_alloc_config.estimated_bw, estimated); + + link->dpia_bw_alloc_config.estimated_bw = estimated; break;

case DPIA_BW_ALLOC_CAPS_CHANGED:

- DC_LOG_DEBUG("%s: *** BW ALLOC CAPABILITY CHANGED for DP-TX Request ***\n", __func__); + DC_LOG_ERROR("%s: BW ALLOC CAPABILITY CHANGED to Disabled for link(%d)\n", + __func__, link->link_index); link->dpia_bw_alloc_config.bw_alloc_enabled = false; break; } @@ -409,11 +387,11 @@ int dpia_handle_usb4_bandwidth_allocation_for_link(struct dc_link *link, int pea set_usb4_req_bw_req(link, link->dpia_bw_alloc_config.sink_max_bw);

do { - if (!(timeout > 0)) + if (timeout > 0) timeout--; else break; - fsleep(10 * 1000); + msleep(10); } while (!get_cm_response_ready_flag(link));

if (!timeout) @@ -428,37 +406,36 @@ int dpia_handle_usb4_bandwidth_allocation_for_link(struct dc_link *link, int pea out: return ret; } -int link_dp_dpia_allocate_usb4_bandwidth_for_stream(struct dc_link *link, int req_bw) + +bool link_dp_dpia_allocate_usb4_bandwidth_for_stream(struct dc_link *link, int req_bw) { - int ret = 0; + bool ret = false; uint8_t timeout = 10;

+ DC_LOG_DEBUG("%s: ENTER: link(%d), hpd_status(%d), current allocated_bw(%d), req_bw(%d)\n", + __func__, link->link_index, link->hpd_status, + link->dpia_bw_alloc_config.sink_allocated_bw, req_bw); + if (!get_bw_alloc_proceed_flag(link)) goto out;

- /* - * Sometimes stream uses same timing parameters as the already - * allocated max sink bw so no need to re-alloc - */ - if (req_bw != link->dpia_bw_alloc_config.sink_allocated_bw) { - set_usb4_req_bw_req(link, req_bw); - do { - if (!(timeout > 0)) - timeout--; - else - break; - udelay(10 * 1000); - } while (!get_cm_response_ready_flag(link)); + set_usb4_req_bw_req(link, req_bw); + do { + if (timeout > 0) + timeout--; + else + break; + msleep(10); + } while (!get_cm_response_ready_flag(link));

- if (!timeout) - ret = 0;// ERROR TIMEOUT waiting for response for allocating bw - else if (link->dpia_bw_alloc_config.sink_allocated_bw > 0) - ret = get_host_router_total_bw(link, HOST_ROUTER_BW_ALLOCATED); - } + if (timeout) + ret = true;

out: + DC_LOG_DEBUG("%s: EXIT: timeout(%d), ret(%d)\n", __func__, timeout, ret); return ret; } + bool dpia_validate_usb4_bw(struct dc_link **link, int *bw_needed_per_dpia, const unsigned int num_dpias) { bool ret = true; diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.h b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.h index 7292690383ae..981bc4eb6120 100644 --- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.h +++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.h @@ -59,9 +59,9 @@ bool link_dp_dpia_set_dptx_usb4_bw_alloc_support(struct dc_link *link); * @link: pointer to the dc_link struct instance * @req_bw: Bw requested by the stream * - * return: allocated bw else return 0 + * return: true if allocated successfully */ -int link_dp_dpia_allocate_usb4_bandwidth_for_stream(struct dc_link *link, int req_bw); +bool link_dp_dpia_allocate_usb4_bandwidth_for_stream(struct dc_link *link, int req_bw);

/* * Handle the USB4 BW Allocation related functionality here: