[PATCH 1/2] lib/igt_kms: add helpers for big joiner debugfs

[Sharma, Swati2]

Hi Bhanu,

On 17-Jan-24 11:46 PM, Modem, Bhanuprakash wrote:
> 
> On 10-01-2024 05:09 pm, Kunal Joshi wrote:
>> From: Swati Sharma <swati2.sharma at intel.com>
>>
>> Add helpers for big joiner debugfs.
>>
>> Signed-off-by: Swati Sharma <swati2.sharma at intel.com>
>> Signed-off-by: Kunal Joshi <kunal1.joshi at intel.com>
>> ---
>>   lib/igt_kms.c | 75 +++++++++++++++++++++++++++++++++++++++++++++++++++
>>   lib/igt_kms.h |  3 +++
>>   2 files changed, 78 insertions(+)
>>
>> diff --git a/lib/igt_kms.c b/lib/igt_kms.c
>> index e4dea1a60..0208eccc4 100644
>> --- a/lib/igt_kms.c
>> +++ b/lib/igt_kms.c
>> @@ -6368,3 +6368,78 @@ int get_num_scalers(int drm_fd, enum pipe pipe)
>>       return num_scalers;
>>   }
>> +
>> +static int write_bigjoiner_debugfs(int drmfd, char *connector_name, 
>> const char *file_name,
>> +                   const char *write_buf)
> 
> IMHO, we need to drop this static function and move the logic to 
> igt_force_bigjoiner_enable()

Why?

> 
>> +{
>> +    int debugfs_fd = igt_debugfs_dir(drmfd);
>> +    int len = strlen(write_buf);
>> +    int ret;
>> +    char file_path[128] = {0};
>> +
>> +    sprintf(file_path, "%s/%s", connector_name, file_name);
>> +
>> +    ret = igt_sysfs_write(debugfs_fd, file_path, write_buf, len);
>> +
>> +    close(debugfs_fd);
>> +
>> +    if (ret > 0)
>> +        return 0;
>> +
>> +    return ret;
>> +}
>> +
>> +static bool check_bigjoiner_debugfs(int drmfd, char *connector_name,
>> +                    const char *check_str)
> 
> we need to drop this static function and move the logic to 
> igt_is_force_bigjoiner_enabled()
> 
>> +{
>> +    char file_name[128] = {0};
>> +    char buf[512];
>> +
>> +    sprintf(file_name, "%s/i915_bigjoiner_force_enable", 
>> connector_name);
>> +
>> +    igt_debugfs_read(drmfd, file_name, buf);
>> +
>> +    return strstr(buf, check_str);
>> +}
>> +
>> +/**
>> + * igt_is_force_bigjoiner_enabled:
>> + * @drmfd: A drm file descriptor
>> + * @connector_name: Name of the libdrm connector we're going to use
>> + *
>> + * Returns: True if Big Joiner is force enabled (via debugfs) for the 
>> given connector,
>> + * false otherwise.
>> + */
>> +bool igt_is_force_bigjoiner_enabled(int drmfd, char *connector_name)
>> +{
>> +    return check_bigjoiner_debugfs(drmfd, connector_name, "Bigjoiner 
>> enable: 1");
>> +}
>> +
>> +/**
>> + * igt_force_bigjoiner_enable:
>> + * @drmfd: A drm file descriptor
>> + * @connector_name: Name of the libdrm connector we're going to use
>> + *
>> + * Returns: 0 on success or negative error code, in case of failure.
>> + */
>> +int igt_force_bigjoiner_enable(int drmfd, char *connector_name, bool 
>> enable)
>> +{
>> +    return write_bigjoiner_debugfs(drmfd, connector_name, 
>> "i915_bigjoiner_force_enable", enable ? "1" : "0");
>> +}
>> +
>> +/**
>> + * igt_get_bigjoiner_debugfs_fd:
> 
> Not understood the purpose of this helper.
> 
> igt_debugfs_connector_dir() will give the directory fd, then we can 
> perform igt_debugfs_simple_read() or igt_sysfs_write() with that fd.

This is getting used here 
https://patchwork.freedesktop.org/patch/574033/?series=128266&rev=2

> 
> - Bhanu
> 
>> + * @drmfd: A drm file descriptor
>> + * @connector_name: Name of the libdrm connector we're going to use
>> + *
>> + * Returns: fd of the Big Joiner debugfs for the given connector,
>> + * else returns -1.
>> + */
>> +int igt_get_bigjoiner_debugfs_fd(int drmfd, char *connector_name)
>> +{
>> +    char file_name[128] = {0};
>> +
>> +    sprintf(file_name, "%s/i915_bigjoiner_force_enable", 
>> connector_name);
>> +
>> +    return openat(igt_debugfs_dir(drmfd), file_name, O_WRONLY);
>> +}
>> diff --git a/lib/igt_kms.h b/lib/igt_kms.h
>> index b3882808b..2d000d54d 100644
>> --- a/lib/igt_kms.h
>> +++ b/lib/igt_kms.h
>> @@ -1218,5 +1218,8 @@ 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(int drm_fd, enum pipe pipe);
>> +bool igt_is_force_bigjoiner_enabled(int drmfd, char *connector_name);
>> +int igt_force_bigjoiner_enable(int drmfd, char *connector_name, bool 
>> enable);
>> +int igt_get_bigjoiner_debugfs_fd(int drmfd, char *connector_name);
>>   #endif /* __IGT_KMS_H__ */