[PATCH] drm: Use EOPNOTSUPP, not ENOTSUPP

[Souza, Jose]

On Wed, 2019-09-04 at 16:39 +0200, Daniel Vetter wrote:
> - it's what we recommend in our docs:
> 
> https://dri.freedesktop.org/docs/drm/gpu/drm-uapi.html#recommended-ioctl-return-values
> 
> - it's the overwhelmingly used error code for "operation not
>   supported", at least in drm core (slightly less so in drivers):
> 
> $ git grep EOPNOTSUP -- drivers/gpu/drm/*c | wc -l
> 83
> $ git grep ENOTSUP -- drivers/gpu/drm/*c | wc -l
> 5
> 
> - include/linux/errno.h makes it fairly clear that these are for
> nfsv3
>   (plus they also have error codes above 512, which is the block with
>   some special behaviour ...)
> 
> /* Defined for the NFSv3 protocol */
> 
> If the above isn't reflecting current practice, then I guess we
> should
> at least update the docs.

Hopefully this will not break any userspace 

Reviewed-by: José Roberto de Souza <jose.souza at intel.com>

> 
> Cc: José Roberto de Souza <jose.souza at intel.com>
> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Cc: Maxime Ripard <mripard at kernel.org>
> Cc: Sean Paul <sean at poorly.run>
> Cc: Alex Deucher <alexander.deucher at amd.com>
> Cc: Andres Rodriguez <andresx7 at gmail.com>
> Cc: Noralf Trønnes <noralf at tronnes.org>
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> ---
>  drivers/gpu/drm/drm_edid.c     | 6 +++---
>  drivers/gpu/drm/drm_mipi_dbi.c | 2 +-
>  2 files changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 82a4ceed3fcf..12c783f4d956 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -3719,7 +3719,7 @@ cea_db_offsets(const u8 *cea, int *start, int
> *end)
>  		if (*end < 4 || *end > 127)
>  			return -ERANGE;
>  	} else {
> -		return -ENOTSUPP;
> +		return -EOPNOTSUPP;
>  	}
>  
>  	return 0;
> @@ -4188,7 +4188,7 @@ int drm_edid_to_sad(struct edid *edid, struct
> cea_sad **sads)
>  
>  	if (cea_revision(cea) < 3) {
>  		DRM_DEBUG_KMS("SAD: wrong CEA revision\n");
> -		return -ENOTSUPP;
> +		return -EOPNOTSUPP;
>  	}
>  
>  	if (cea_db_offsets(cea, &start, &end)) {
> @@ -4249,7 +4249,7 @@ int drm_edid_to_speaker_allocation(struct edid
> *edid, u8 **sadb)
>  
>  	if (cea_revision(cea) < 3) {
>  		DRM_DEBUG_KMS("SAD: wrong CEA revision\n");
> -		return -ENOTSUPP;
> +		return -EOPNOTSUPP;
>  	}
>  
>  	if (cea_db_offsets(cea, &start, &end)) {
> diff --git a/drivers/gpu/drm/drm_mipi_dbi.c
> b/drivers/gpu/drm/drm_mipi_dbi.c
> index c4ee2709a6f3..f8154316a3b0 100644
> --- a/drivers/gpu/drm/drm_mipi_dbi.c
> +++ b/drivers/gpu/drm/drm_mipi_dbi.c
> @@ -955,7 +955,7 @@ static int mipi_dbi_typec1_command(struct
> mipi_dbi *dbi, u8 *cmd,
>  	int ret;
>  
>  	if (mipi_dbi_command_is_read(dbi, *cmd))
> -		return -ENOTSUPP;
> +		return -EOPNOTSUPP;
>  
>  	MIPI_DBI_DEBUG_COMMAND(*cmd, parameters, num);
>