[PATCH i-g-t 1/7] lib/igt_kms: add DP link management helper functions
Imre Deak
imre.deak at intel.com
Mon Sep 23 11:47:19 UTC 2024
On Mon, Sep 23, 2024 at 02:55:43AM +0530, Kunal Joshi wrote:
> Added helper functions for below
> - read current/max link_rate/lane_count
> - forcing link retraining
> - forcing link training failures
> - read pending retrain
> - read pending link training failures
> - checking output supports forcing lt failures
> - force link_rate/lane_count
>
> v2: combine all link training debugfs in one patch (Imre)
> remove unwanted valid output check (Imre)
> return link_rate/lane_count marked with '*' or an error (Imre)
>
> v3: add debugfs_connector_read/write helpers (Imre)
>
> Signed-off-by: Kunal Joshi <kunal1.joshi at intel.com>
> ---
> lib/igt_kms.c | 307 ++++++++++++++++++++++++++++++++++++++++++++++++++
> lib/igt_kms.h | 10 ++
> 2 files changed, 317 insertions(+)
>
> diff --git a/lib/igt_kms.c b/lib/igt_kms.c
> index b40470c02..c79d800eb 100644
> --- a/lib/igt_kms.c
> +++ b/lib/igt_kms.c
> @@ -47,6 +47,7 @@
> #include <poll.h>
> #include <errno.h>
> #include <time.h>
> +#include <ctype.h>
>
> #include <i915_drm.h>
>
> @@ -6713,3 +6714,309 @@ int get_num_scalers(igt_display_t *display, enum pipe pipe)
>
> return num_scalers;
> }
> +
> +/**
> + * igt_parse_marked_value:
> + * @buf: Buffer containing the content to parse
> + * @marked_char: The character marking the value to parse
> + * @result: Pointer to store the parsed value
> + *
> + * Finds the integer value in the buffer that is marked by the given character.
> + *
> + * Returns: 0 on success, -1 on failure
> + */
> +static int igt_parse_marked_value(const char *buf, char marked_char, int *result)
> +{
> + char *star_ptr, *val_ptr;
It's not necessarily the '*' character, so the above should be called marked_ptr, or
remove the parameter, since always '*' is passed to the function.
> +
> + /*
> + * Look for the marked character
> + */
> + star_ptr = strchr(buf, marked_char);
> +
> + if (star_ptr) {
> + val_ptr = star_ptr - 1;
> + while (val_ptr > buf && isdigit(*val_ptr))
> + val_ptr--;
> + val_ptr++;
> + if (sscanf(val_ptr, "%d", result) == 1)
> + return 0;
> + }
> + return -1;
> +}
> +
> +/**
> + * igt_debugfs_read_connector_file:
> + * @drm_fd: A drm file descriptor
> + * @conn_name: Name of the output connector
> + * @filename: The file to read from in the connector's directory
> + * @buf: Buffer to store the read content
> + * @buf_size: Size of the buffer
> + *
> + * Reads from a specific file in the connector's debugfs directory.
> + *
> + * Returns: 0 on success, -1 on failure.
> + */
> +static int igt_debugfs_read_connector_file(int drm_fd, char *conn_name,
> + const char *filename, char *buf,
> + size_t buf_size)
> +{
> + int dir, res;
> +
> + dir = igt_debugfs_connector_dir(drm_fd, conn_name, O_RDONLY);
> + igt_assert_f(dir >= 0, "Failed to open debugfs dir for connector %s\n", conn_name);
> +
> + res = igt_debugfs_simple_read(dir, filename, buf, buf_size);
> + close(dir);
> +
> + if (res < 0)
> + return -1;
> +
> + return 0;
> +}
> +
> +/**
> + * igt_debugfs_write_connector_file:
> + * @drm_fd: A drm file descriptor
> + * @conn_name: Name of the output connector
> + * @filename: The file to write to in the connector's directory
> + * @data: Data to write to the file
> + * @data_size: Size of the data to write
> + *
> + * Writes to a specific file in the connector's debugfs directory.
> + *
> + * Returns: 0 on success, -1 on failure.
> + */
> +static int igt_debugfs_write_connector_file(int drm_fd, char *conn_name,
> + const char *filename, const char *data,
> + size_t data_size)
> +{
> + int dir, res;
> +
> + dir = igt_debugfs_connector_dir(drm_fd, conn_name, O_DIRECTORY);
Using O_RDONLY here as well is enough, the directory does not change.
> + igt_assert_f(dir >= 0, "Failed to open debugfs dir for connector %s\n",
> + conn_name);
> +
> + res = igt_sysfs_write(dir, filename, data, data_size);
> + close(dir);
> +
> + if (res < 0)
> + return -1;
> +
> + return 0;
> +}
> +
> +/**
> + * igt_get_current_link_rate:
> + * @drm_fd: A drm file descriptor
> + * @output: Target output
> + *
> + * Returns: link_rate if set for output else -1
> + */
> +int igt_get_current_link_rate(int drm_fd, igt_output_t *output)
> +{
> + char buf[512];
> + int res, ret;
> +
> + res = igt_debugfs_read_connector_file(drm_fd, output->name,
> + "i915_dp_force_link_rate",
> + buf, sizeof(buf));
> + igt_assert_f(res == 0, "Unable to read %s/i915_dp_force_link_rate\n",
> + output->name);
> + res = igt_parse_marked_value(buf, '*', &ret);
> + igt_assert_f(res == 0, "Output %s not enabled\n", output->name);
> + return ret;
> +}
> +
> +/**
> + * igt_get_current_lane_count:
> + * @drm_fd: A drm file descriptor
> + * @output: Target output
> + *
> + * Returns: lane_count if set for output else -1
> + */
> +int igt_get_current_lane_count(int drm_fd, igt_output_t *output)
> +{
> + char buf[512];
> + int res, ret;
> +
> + res = igt_debugfs_read_connector_file(drm_fd, output->name,
> + "i915_dp_force_lane_count",
> + buf, sizeof(buf));
> + igt_assert_f(res == 0, "Unable to read %s/i915_dp_force_lane_count\n",
> + output->name);
> + res = igt_parse_marked_value(buf, '*', &ret);
> + igt_assert_f(res == 0, "Output %s not enabled\n", output->name);
> + return ret;
> +}
> +
> +/**
> + * igt_get_max_link_rate:
> + * @drm_fd: A drm file descriptor
> + * @output: Target output
> + *
> + * Returns: max_link_rate
> + */
> +int igt_get_max_link_rate(int drm_fd, igt_output_t *output)
> +{
> + char buf[512];
> + int res, ret;
> +
> + res = igt_debugfs_read_connector_file(drm_fd, output->name,
> + "i915_dp_max_link_rate",
> + buf, sizeof(buf));
> + igt_assert_f(res == 0, "Unable to read %s/i915_dp_max_link_rate\n",
> + output->name);
> +
> + sscanf(buf, "%d", &ret);
> + return ret;
> +}
> +
> +/**
> + * igt_get_max_link_rate:
> + * @drm_fd: A drm file descriptor
> + * @output: Target output
> + *
> + * Returns: max_link_rate
> + */
> +int igt_get_max_lane_count(int drm_fd, igt_output_t *output)
> +{
> + char buf[512];
> + int res, ret;
> +
> + res = igt_debugfs_read_connector_file(drm_fd, output->name,
> + "i915_dp_max_lane_count",
> + buf, sizeof(buf));
> + igt_assert_f(res == 0, "Unable to read %s/i915_dp_max_lane_count\n",
> + output->name);
> +
> + sscanf(buf, "%d", &ret);
> + return ret;
> +}
> +
> +/**
> + * igt_force_link_retrain:
> + * @drm_fd: A drm file descriptor
> + * @output: Target output
> + * @retrain_count: number of retraining required
> + *
> + * Force link retrain on the output.
> + */
> +void igt_force_link_retrain(int drm_fd, igt_output_t *output, int retrain_count)
> +{
> + char value[2];
> + int res;
> +
> + snprintf(value, sizeof(value), "%d", retrain_count);
> + res = igt_debugfs_write_connector_file(drm_fd, output->name,
> + "i915_dp_force_link_retrain",
> + value, sizeof(value));
This just happens to work, since sizeof(value) is 2. Please use
strlen() instead.
> + igt_assert_f(res == 0, "Unable to write to %s/i915_dp_force_link_retrain\n",
> + output->name);
> +}
> +
> +/**
> + * igt_force_lt_failure:
> + * @drm_fd: A drm file descriptor
> + * @output: Target output
> + * @failure_count: 1 for same link param and
> + * 2 for reduced link params
> + *
> + * Force link training failure on the output.
> + * @failure_count: 1 for retraining with same link params
> + * 2 for retraining with reduced link params
> + */
> +void igt_force_lt_failure(int drm_fd, igt_output_t *output, int failure_count)
> +{
> + char value[2];
> + int res;
> +
> + snprintf(value, sizeof(value), "%d", failure_count);
> + res = igt_debugfs_write_connector_file(drm_fd, output->name,
> + "i915_dp_force_link_training_failure",
> + value, sizeof(value));
Use strlen().
With the above fixed this is:
Reviewed-by: Imre Deak <imre.deak at intel.com>
> + igt_assert_f(res == 0, "Unable to write to %s/i915_dp_force_link_training_failure\n",
> + output->name);
> +}
> +
> +/**
> + * igt_get_dp_link_retrain_disabled:
> + * @drm_fd: A drm file descriptor
> + * @output: Target output
> + *
> + * Returns: True if link retrain disabled, false otherwise
> + */
> +bool igt_get_dp_link_retrain_disabled(int drm_fd, igt_output_t *output)
> +{
> + char buf[512];
> + int res;
> +
> + res = igt_debugfs_read_connector_file(drm_fd, output->name,
> + "i915_dp_link_retrain_disabled",
> + buf, sizeof(buf));
> + igt_assert_f(res == 0, "Unable to read %s/i915_dp_link_retrain_disabled\n",
> + output->name);
> + return strstr(buf, "yes");
> +}
> +
> +/**
> + * Checks if the force link training failure debugfs
> + * is available for a specific output.
> + *
> + * @drmfd: file descriptor of the DRM device.
> + * @output: output to check.
> + * Returns:
> + * true if the debugfs is available, false otherwise.
> + */
> +bool igt_has_force_link_training_failure_debugfs(int drmfd, igt_output_t *output)
> +{
> + char buf[512];
> + int res;
> +
> + res = igt_debugfs_read_connector_file(drmfd, output->name,
> + "i915_dp_link_retrain_disabled",
> + buf, sizeof(buf));
> + return res == 0;
> +}
> +
> +/**
> + * igt_get_dp_pending_lt_failures:
> + * @drm_fd: A drm file descriptor
> + * @output: Target output
> + *
> + * Returns: Number of pending link training failures.
> + */
> +int igt_get_dp_pending_lt_failures(int drm_fd, igt_output_t *output)
> +{
> + char buf[512];
> + int res, ret;
> +
> + res = igt_debugfs_read_connector_file(drm_fd, output->name,
> + "i915_dp_force_link_training_failure",
> + buf, sizeof(buf));
> + igt_assert_f(res == 0, "Unable to read %s/i915_dp_force_link_training_failure\n",
> + output->name);
> + sscanf(buf, "%d", &ret);
> + return ret;
> +}
> +
> +/**
> + * igt_dp_pending_retrain:
> + * @drm_fd: A drm file descriptor
> + * @output: Target output
> + *
> + * Returns: Number of pending link retrains.
> + */
> +int igt_get_dp_pending_retrain(int drm_fd, igt_output_t *output)
> +{
> + char buf[512];
> + int res, ret;
> +
> + res = igt_debugfs_read_connector_file(drm_fd, output->name,
> + "i915_dp_force_link_retrain",
> + buf, sizeof(buf));
> + igt_assert_f(res == 0, "Unable to read %s/i915_dp_force_link_retrain\n",
> + output->name);
> + sscanf(buf, "%d", &ret);
> + return ret;
> +}
> diff --git a/lib/igt_kms.h b/lib/igt_kms.h
> index 25ba50916..7d9c28d81 100644
> --- a/lib/igt_kms.h
> +++ b/lib/igt_kms.h
> @@ -1224,5 +1224,15 @@ bool intel_pipe_output_combo_valid(igt_display_t *display);
> bool igt_check_output_is_dp_mst(igt_output_t *output);
> int igt_get_dp_mst_connector_id(igt_output_t *output);
> int get_num_scalers(igt_display_t *display, enum pipe pipe);
> +int igt_get_current_lane_count(int drm_fd, igt_output_t *output);
> +int igt_get_current_link_rate(int drm_fd, igt_output_t *output);
> +int igt_get_max_link_rate(int drm_fd, igt_output_t *output);
> +int igt_get_max_lane_count(int drm_fd, igt_output_t *output);
> +void igt_force_link_retrain(int drm_fd, igt_output_t *output, int retrain_count);
> +void igt_force_lt_failure(int drm_fd, igt_output_t *output, int failure_count);
> +bool igt_get_dp_link_retrain_disabled(int drm_fd, igt_output_t *output);
> +bool igt_has_force_link_training_failure_debugfs(int drmfd, igt_output_t *output);
> +int igt_get_dp_pending_lt_failures(int drm_fd, igt_output_t *output);
> +int igt_get_dp_pending_retrain(int drm_fd, igt_output_t *output);
>
> #endif /* __IGT_KMS_H__ */
> --
> 2.43.0
>
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