[igt-dev] [PATCH i-g-t v4 6/8] lib/dsc: Add helpers for VDSC Fractional BPP debugfs entry

[Hogander, Jouni]

Hello Swati. One inline comment below. Sorry for missing it on first
round.

On Thu, 2023-01-12 at 13:05 +0530, Swati Sharma wrote:
> Helper functions are added for getting/setting VDSC Fractional BPP
> debugfs entry.
> 
> v2: -improved func description (Ankit)
>     -increased buff size (Ankit)
>     -asserted bpp_prec (Ankit)
> 
> Signed-off-by: Swati Sharma <swati2.sharma at intel.com>
> ---
>  lib/igt_dsc.c | 84
> +++++++++++++++++++++++++++++++++++++++++++++++++++
>  lib/igt_dsc.h |  5 +++
>  2 files changed, 89 insertions(+)
> 
> diff --git a/lib/igt_dsc.c b/lib/igt_dsc.c
> index 269d574e9..e5e67a469 100644
> --- a/lib/igt_dsc.c
> +++ b/lib/igt_dsc.c
> @@ -198,3 +198,87 @@ int igt_get_dsc_ycbcr420_debugfs_fd(int drmfd,
> char *connector_name)
>  
>         return openat(igt_debugfs_dir(drmfd), file_name, O_WRONLY);
>  }
> +
> +static
> +bool check_dsc_fractional_bpp_debugfs(int drmfd, char
> *connector_name,
> +                                     const char *check_str)
> +{
> +       char file_name[128] = {0};
> +       char buf[512];
> +
> +       sprintf(file_name, "%s/i915_dsc_fractional_bpp",
> connector_name);
> +
> +       igt_debugfs_read(drmfd, file_name, buf);
> +
> +       return strstr(buf, check_str);
> +}
> +
> +/*
> + * igt_get_dsc_fractional_bpp_supported:
> + * @drmfd: A drm file descriptor
> + * @connector_name: Name of the libdrm connector we're going to use
> + *
> + * Returns: The dsc sink bpp precision.
> + *         Precision value of
> + *                             16 => 1/16
> + *                             8  => 1/8
> + *                             1  => fractional bpp not supported
> + */
> +int igt_get_dsc_fractional_bpp_supported(int drmfd, char
> *connector_name)
> +{
> +       char file_name[128] = {0};
> +       char buf[512];
> +       char *start_loc;
> +       int bpp_prec;
> +
> +       sprintf(file_name, "%s/i915_dsc_fec_support",
> connector_name);
> +       igt_debugfs_read(drmfd, file_name, buf);
> +
> +       igt_assert(start_loc = strstr(buf, "DSC_Sink_BPP_Precision:
> "));
> +       igt_assert_eq(sscanf(start_loc, "DSC_Sink_BPP_Precision: %d",
> &bpp_prec), 1);
> +       igt_assert(bpp_prec > 0);
> +
> +       return bpp_prec;
> +}
> +
> +/*
> + * igt_is_force_dsc_fractional_bpp_enabled:
> + * @drmfd: A drm file descriptor
> + * @connector_name: Name of the libdrm connector we're going to use
> + *
> + * Returns: True if DSC Fractional BPP is force enabled (via
> debugfs) for the given connector,
> + * false otherwise.
> + */
> +bool igt_is_force_dsc_fractional_bpp_enabled(int drmfd, char
> *connector_name)
> +{
> +       return check_dsc_fractional_bpp_debugfs(drmfd,
> connector_name, "Force_DSC_Fractional_BPP_Enable: yes");
> +}
> +
> +/*
> + * igt_force_dsc_fractional_bpp_enable:
> + * @drmfd: A drm file descriptor
> + * @connector_name: Name of the libdrm connector we're going to use
> + *
> + * Returns: 1 on success or negative error code, in case of failure.

0 = success.

> + */
> +int igt_force_dsc_fractional_bpp_enable(int drmfd, char
> *connector_name)
> +{
> +       return write_dsc_debugfs(drmfd, connector_name,
> "i915_dsc_fractional_bpp", "1");
> +}
> +
> +/*
> + * igt_get_dsc_fractional_bpp_debugfs_fd:
> + * @drmfd: A drm file descriptor
> + * @connector_name: Name of the libdrm connector we're going to use
> + *
> + * Returns: fd of the DSC Fractional BPP debugfs for the given
> connector,
> + * else returns -1.
> + */
> +int igt_get_dsc_fractional_bpp_debugfs_fd(int drmfd, char
> *connector_name)
> +{
> +       char file_name[128] = {0};
> +
> +       sprintf(file_name, "%s/i915_dsc_fractional_bpp",
> connector_name);
> +
> +       return openat(igt_debugfs_dir(drmfd), file_name, O_WRONLY);
> +}
> diff --git a/lib/igt_dsc.h b/lib/igt_dsc.h
> index e2b039f42..7dc958406 100644
> --- a/lib/igt_dsc.h
> +++ b/lib/igt_dsc.h
> @@ -7,6 +7,7 @@
>  #define IGT_DSC_H
>  
>  #include "igt_fb.h"
> +#include "igt_core.h"
>  
>  bool igt_is_dsc_supported(int drmfd, char *connector_name);
>  bool igt_is_fec_supported(int drmfd, char *connector_name);
> @@ -19,5 +20,9 @@ bool igt_is_dsc_ycbcr420_supported(int drmfd, char
> *connector_name);
>  bool igt_is_force_dsc_ycbcr420_enabled(int drmfd, char
> *connector_name);
>  int igt_force_dsc_ycbcr420_enable(int drmfd, char *connector_name);
>  int igt_get_dsc_ycbcr420_debugfs_fd(int drmfd, char
> *connector_name);
> +int igt_get_dsc_fractional_bpp_supported(int drmfd, char
> *connector_name);
> +bool igt_is_force_dsc_fractional_bpp_enabled(int drmfd, char
> *connector_name);
> +int igt_force_dsc_fractional_bpp_enable(int drmfd, char
> *connector_name);
> +int igt_get_dsc_fractional_bpp_debugfs_fd(int drmfd, char
> *connector_name);
>  
>  #endif