From 70487a99eeff5d0aa8104bd4eb236f318395658f Mon Sep 17 00:00:00 2001 From: Wayne Lin Date: Fri, 10 Dec 2021 15:04:00 -0800 Subject: [PATCH] drm/amd/display: Add debugfs entry for ILR [Why & How] In order to know the intermediate link rates supported by the eDP panel and test to select the optimized link rate to save power, create a new debugfs entry "ilr_setting" for setting ILR. Reviewed-by: Aurabindo Jayamohanan Pillai Acked-by: Pavle Kotarac Tested-by: Daniel Wheeler Signed-off-by: Wayne Lin Signed-off-by: Alex Deucher --- .../amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 134 ++++++++++++++++++ 1 file changed, 134 insertions(+) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c index dc55a736e198..ded64d0e34c1 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c @@ -2755,6 +2755,138 @@ static const struct { {"internal_display", &internal_display_fops} }; +/* + * Returns supported customized link rates by this eDP panel. + * Example usage: cat /sys/kernel/debug/dri/0/eDP-x/ilr_setting + */ +static int edp_ilr_show(struct seq_file *m, void *unused) +{ + struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(m->private); + struct dc_link *link = aconnector->dc_link; + uint8_t supported_link_rates[16]; + uint32_t link_rate_in_khz; + uint32_t entry = 0; + uint8_t dpcd_rev; + + memset(supported_link_rates, 0, sizeof(supported_link_rates)); + dm_helpers_dp_read_dpcd(link->ctx, link, DP_SUPPORTED_LINK_RATES, + supported_link_rates, sizeof(supported_link_rates)); + + dpcd_rev = link->dpcd_caps.dpcd_rev.raw; + + if (dpcd_rev >= DP_DPCD_REV_13 && + (supported_link_rates[entry+1] != 0 || supported_link_rates[entry] != 0)) { + + for (entry = 0; entry < 16; entry += 2) { + link_rate_in_khz = (supported_link_rates[entry+1] * 0x100 + + supported_link_rates[entry]) * 200; + seq_printf(m, "[%d] %d kHz\n", entry/2, link_rate_in_khz); + } + } else { + seq_printf(m, "ILR is not supported by this eDP panel.\n"); + } + + return 0; +} + +/* + * Set supported customized link rate to eDP panel. + * + * echo > ilr_setting + * + * for example, supported ILR : [0] 1620000 kHz [1] 2160000 kHz [2] 2430000 kHz ... + * echo 4 1 > /sys/kernel/debug/dri/0/eDP-x/ilr_setting + * to set 4 lanes and 2.16 GHz + */ +static ssize_t edp_ilr_write(struct file *f, const char __user *buf, + size_t size, loff_t *pos) +{ + struct amdgpu_dm_connector *connector = file_inode(f)->i_private; + struct dc_link *link = connector->dc_link; + struct amdgpu_device *adev = drm_to_adev(connector->base.dev); + struct dc *dc = (struct dc *)link->dc; + struct dc_link_settings prefer_link_settings; + char *wr_buf = NULL; + const uint32_t wr_buf_size = 40; + /* 0: lane_count; 1: link_rate */ + int max_param_num = 2; + uint8_t param_nums = 0; + long param[2]; + bool valid_input = true; + + if (size == 0) + return -EINVAL; + + wr_buf = kcalloc(wr_buf_size, sizeof(char), GFP_KERNEL); + if (!wr_buf) + return -ENOMEM; + + if (parse_write_buffer_into_params(wr_buf, wr_buf_size, + (long *)param, buf, + max_param_num, + ¶m_nums)) { + kfree(wr_buf); + return -EINVAL; + } + + if (param_nums <= 0) { + kfree(wr_buf); + return -EINVAL; + } + + switch (param[0]) { + case LANE_COUNT_ONE: + case LANE_COUNT_TWO: + case LANE_COUNT_FOUR: + break; + default: + valid_input = false; + break; + } + + if (param[1] >= link->dpcd_caps.edp_supported_link_rates_count) + valid_input = false; + + if (!valid_input) { + kfree(wr_buf); + DRM_DEBUG_DRIVER("Invalid Input value. No HW will be programmed\n"); + prefer_link_settings.use_link_rate_set = false; + dc_link_set_preferred_training_settings(dc, NULL, NULL, link, true); + return size; + } + + /* save user force lane_count, link_rate to preferred settings + * spread spectrum will not be changed + */ + prefer_link_settings.link_spread = link->cur_link_settings.link_spread; + prefer_link_settings.lane_count = param[0]; + prefer_link_settings.use_link_rate_set = true; + prefer_link_settings.link_rate_set = param[1]; + prefer_link_settings.link_rate = link->dpcd_caps.edp_supported_link_rates[param[1]]; + + mutex_lock(&adev->dm.dc_lock); + dc_link_set_preferred_training_settings(dc, &prefer_link_settings, + NULL, link, false); + mutex_unlock(&adev->dm.dc_lock); + + kfree(wr_buf); + return size; +} + +static int edp_ilr_open(struct inode *inode, struct file *file) +{ + return single_open(file, edp_ilr_show, inode->i_private); +} + +static const struct file_operations edp_ilr_debugfs_fops = { + .owner = THIS_MODULE, + .open = edp_ilr_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, + .write = edp_ilr_write +}; + void connector_debugfs_init(struct amdgpu_dm_connector *connector) { int i; @@ -2775,6 +2907,8 @@ void connector_debugfs_init(struct amdgpu_dm_connector *connector) ¤t_backlight_fops); debugfs_create_file("amdgpu_target_backlight_pwm", 0444, dir, connector, &target_backlight_fops); + debugfs_create_file("ilr_setting", 0644, dir, connector, + &edp_ilr_debugfs_fops); } for (i = 0; i < ARRAY_SIZE(connector_debugfs_entries); i++) {