From cca912e0a6b49f45c588e7cc50d3ad13bb859ca5 Mon Sep 17 00:00:00 2001 From: Eryk Brol Date: Fri, 12 Feb 2021 15:25:22 -0500 Subject: [PATCH] drm/amd/display: Add max bpc debugfs [Why] Useful for testing when setting a max bpc value higher than the default is required [How] Allow for reading/writing of the max_requested_bpc property of the connector Tested-by: Daniel Wheeler Signed-off-by: Eryk Brol Signed-off-by: Ilya Bakoulin Reviewed-by: Mikita Lipski Acked-by: Rodrigo Siqueira Signed-off-by: Alex Deucher --- .../drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 153 ++++++++++++++++++++- 1 file changed, 152 insertions(+), 1 deletion(-) 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 f7408d0..859560a 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 @@ -2152,6 +2152,149 @@ static ssize_t dp_dsc_slice_bpg_offset_read(struct file *f, char __user *buf, return result; } + +/* + * function description: Read max_requested_bpc property from the connector + * + * Access it with the following command: + * + * cat /sys/kernel/debug/dri/0/DP-X/max_bpc + * + */ +static ssize_t dp_max_bpc_read(struct file *f, char __user *buf, + size_t size, loff_t *pos) +{ + struct amdgpu_dm_connector *aconnector = file_inode(f)->i_private; + struct drm_connector *connector = &aconnector->base; + struct drm_device *dev = connector->dev; + struct dm_connector_state *state; + ssize_t result = 0; + char *rd_buf = NULL; + char *rd_buf_ptr = NULL; + const uint32_t rd_buf_size = 10; + int r; + + rd_buf = kcalloc(rd_buf_size, sizeof(char), GFP_KERNEL); + + if (!rd_buf) + return -ENOMEM; + + mutex_lock(&dev->mode_config.mutex); + drm_modeset_lock(&dev->mode_config.connection_mutex, NULL); + + if (connector->state == NULL) + goto unlock; + + state = to_dm_connector_state(connector->state); + + rd_buf_ptr = rd_buf; + snprintf(rd_buf_ptr, rd_buf_size, + "%u\n", + state->base.max_requested_bpc); + + while (size) { + if (*pos >= rd_buf_size) + break; + + r = put_user(*(rd_buf + result), buf); + if (r) { + result = r; /* r = -EFAULT */ + goto unlock; + } + buf += 1; + size -= 1; + *pos += 1; + result += 1; + } +unlock: + drm_modeset_unlock(&dev->mode_config.connection_mutex); + mutex_unlock(&dev->mode_config.mutex); + kfree(rd_buf); + return result; +} + + +/* + * function description: Set max_requested_bpc property on the connector + * + * This function will not force the input BPC on connector, it will only + * change the max value. This is equivalent to setting max_bpc through + * xrandr. + * + * The BPC value written must be >= 6 and <= 16. Values outside of this + * range will result in errors. + * + * BPC values: + * 0x6 - 6 BPC + * 0x8 - 8 BPC + * 0xa - 10 BPC + * 0xc - 12 BPC + * 0x10 - 16 BPC + * + * Write the max_bpc in the following way: + * + * echo 0x6 > /sys/kernel/debug/dri/0/DP-X/max_bpc + * + */ +static ssize_t dp_max_bpc_write(struct file *f, const char __user *buf, + size_t size, loff_t *pos) +{ + struct amdgpu_dm_connector *aconnector = file_inode(f)->i_private; + struct drm_connector *connector = &aconnector->base; + struct dm_connector_state *state; + struct drm_device *dev = connector->dev; + char *wr_buf = NULL; + uint32_t wr_buf_size = 42; + int max_param_num = 1; + long param[1] = {0}; + uint8_t param_nums = 0; + + if (size == 0) + return -EINVAL; + + wr_buf = kcalloc(wr_buf_size, sizeof(char), GFP_KERNEL); + + if (!wr_buf) { + DRM_DEBUG_DRIVER("no memory to allocate write buffer\n"); + return -ENOSPC; + } + + if (parse_write_buffer_into_params(wr_buf, size, + (long *)param, buf, + max_param_num, + ¶m_nums)) { + kfree(wr_buf); + return -EINVAL; + } + + if (param_nums <= 0) { + DRM_DEBUG_DRIVER("user data not be read\n"); + kfree(wr_buf); + return -EINVAL; + } + + if (param[0] < 6 || param[0] > 16) { + DRM_DEBUG_DRIVER("bad max_bpc value\n"); + kfree(wr_buf); + return -EINVAL; + } + + mutex_lock(&dev->mode_config.mutex); + drm_modeset_lock(&dev->mode_config.connection_mutex, NULL); + + if (connector->state == NULL) + goto unlock; + + state = to_dm_connector_state(connector->state); + state->base.max_requested_bpc = param[0]; +unlock: + drm_modeset_unlock(&dev->mode_config.connection_mutex); + mutex_unlock(&dev->mode_config.mutex); + + kfree(wr_buf); + return size; +} + DEFINE_SHOW_ATTRIBUTE(dp_dsc_fec_support); DEFINE_SHOW_ATTRIBUTE(dmub_fw_state); DEFINE_SHOW_ATTRIBUTE(dmub_tracebuffer); @@ -2263,6 +2406,13 @@ static const struct file_operations dp_dpcd_data_debugfs_fops = { .llseek = default_llseek }; +static const struct file_operations dp_max_bpc_debugfs_fops = { + .owner = THIS_MODULE, + .read = dp_max_bpc_read, + .write = dp_max_bpc_write, + .llseek = default_llseek +}; + static const struct { char *name; const struct file_operations *fops; @@ -2285,7 +2435,8 @@ static const struct { {"dsc_pic_height", &dp_dsc_pic_height_debugfs_fops}, {"dsc_chunk_size", &dp_dsc_chunk_size_debugfs_fops}, {"dsc_slice_bpg", &dp_dsc_slice_bpg_offset_debugfs_fops}, - {"dp_dsc_fec_support", &dp_dsc_fec_support_fops} + {"dp_dsc_fec_support", &dp_dsc_fec_support_fops}, + {"max_bpc", &dp_max_bpc_debugfs_fops} }; #ifdef CONFIG_DRM_AMD_DC_HDCP -- 2.7.4