Re: [PATCH v3 02/16] drm/edid: Break out reading block 0 of the EDID

2021-09-06 Thread Jani Nikula
On Wed, 01 Sep 2021, Douglas Anderson  wrote:
> A future change wants to be able to read just block 0 of the EDID, so
> break it out of drm_do_get_edid() into a sub-function.
>
> This is intended to be a no-op change--just code movement.
>
> Signed-off-by: Douglas Anderson 
> ---
>
> (no changes since v1)
>
>  drivers/gpu/drm/drm_edid.c | 62 +++---
>  1 file changed, 44 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 6325877c5fd6..a22c38482a90 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -1905,6 +1905,43 @@ int drm_add_override_edid_modes(struct drm_connector 
> *connector)
>  }
>  EXPORT_SYMBOL(drm_add_override_edid_modes);
>  
> +static struct edid *drm_do_get_edid_blk0(

Maybe base_block instead of blk0?

> + int (*get_edid_block)(void *data, u8 *buf, unsigned int block,
> +   size_t len),
> + void *data, bool *edid_corrupt, int *null_edid_counter)
> +{
> + int i;
> + u8 *edid;

With void *edid, this function wouldn't need the cast internally.

> +
> + if ((edid = kmalloc(EDID_LENGTH, GFP_KERNEL)) == NULL)
> + return NULL;

Could split the allocation and NULL check to two separate lines per
coding style, while at it?

BR,
Jani.

> +
> + /* base block fetch */
> + for (i = 0; i < 4; i++) {
> + if (get_edid_block(data, edid, 0, EDID_LENGTH))
> + goto out;
> + if (drm_edid_block_valid(edid, 0, false, edid_corrupt))
> + break;
> + if (i == 0 && drm_edid_is_zero(edid, EDID_LENGTH)) {
> + if (null_edid_counter)
> + (*null_edid_counter)++;
> + goto carp;
> + }
> + }
> + if (i == 4)
> + goto carp;
> +
> + return (struct edid *)edid;
> +
> +carp:
> + kfree(edid);
> + return ERR_PTR(-EINVAL);
> +
> +out:
> + kfree(edid);
> + return NULL;
> +}
> +
>  /**
>   * drm_do_get_edid - get EDID data using a custom EDID block read function
>   * @connector: connector we're probing
> @@ -1938,25 +1975,16 @@ struct edid *drm_do_get_edid(struct drm_connector 
> *connector,
>   if (override)
>   return override;
>  
> - if ((edid = kmalloc(EDID_LENGTH, GFP_KERNEL)) == NULL)
> + edid = (u8 *)drm_do_get_edid_blk0(get_edid_block, data,
> +   >edid_corrupt,
> +   >null_edid_counter);
> + if (IS_ERR_OR_NULL(edid)) {
> + if (IS_ERR(edid))
> + connector_bad_edid(connector, edid, 1);
>   return NULL;
> -
> - /* base block fetch */
> - for (i = 0; i < 4; i++) {
> - if (get_edid_block(data, edid, 0, EDID_LENGTH))
> - goto out;
> - if (drm_edid_block_valid(edid, 0, false,
> -  >edid_corrupt))
> - break;
> - if (i == 0 && drm_edid_is_zero(edid, EDID_LENGTH)) {
> - connector->null_edid_counter++;
> - goto carp;
> - }
>   }
> - if (i == 4)
> - goto carp;
>  
> - /* if there's no extensions, we're done */
> + /* if there's no extensions or no connector, we're done */
>   valid_extensions = edid[0x7e];
>   if (valid_extensions == 0)
>   return (struct edid *)edid;
> @@ -2010,8 +2038,6 @@ struct edid *drm_do_get_edid(struct drm_connector 
> *connector,
>  
>   return (struct edid *)edid;
>  
> -carp:
> - connector_bad_edid(connector, edid, 1);
>  out:
>   kfree(edid);
>   return NULL;

-- 
Jani Nikula, Intel Open Source Graphics Center


[PATCH v3 02/16] drm/edid: Break out reading block 0 of the EDID

2021-09-01 Thread Douglas Anderson
A future change wants to be able to read just block 0 of the EDID, so
break it out of drm_do_get_edid() into a sub-function.

This is intended to be a no-op change--just code movement.

Signed-off-by: Douglas Anderson 
---

(no changes since v1)

 drivers/gpu/drm/drm_edid.c | 62 +++---
 1 file changed, 44 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 6325877c5fd6..a22c38482a90 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -1905,6 +1905,43 @@ int drm_add_override_edid_modes(struct drm_connector 
*connector)
 }
 EXPORT_SYMBOL(drm_add_override_edid_modes);
 
+static struct edid *drm_do_get_edid_blk0(
+   int (*get_edid_block)(void *data, u8 *buf, unsigned int block,
+ size_t len),
+   void *data, bool *edid_corrupt, int *null_edid_counter)
+{
+   int i;
+   u8 *edid;
+
+   if ((edid = kmalloc(EDID_LENGTH, GFP_KERNEL)) == NULL)
+   return NULL;
+
+   /* base block fetch */
+   for (i = 0; i < 4; i++) {
+   if (get_edid_block(data, edid, 0, EDID_LENGTH))
+   goto out;
+   if (drm_edid_block_valid(edid, 0, false, edid_corrupt))
+   break;
+   if (i == 0 && drm_edid_is_zero(edid, EDID_LENGTH)) {
+   if (null_edid_counter)
+   (*null_edid_counter)++;
+   goto carp;
+   }
+   }
+   if (i == 4)
+   goto carp;
+
+   return (struct edid *)edid;
+
+carp:
+   kfree(edid);
+   return ERR_PTR(-EINVAL);
+
+out:
+   kfree(edid);
+   return NULL;
+}
+
 /**
  * drm_do_get_edid - get EDID data using a custom EDID block read function
  * @connector: connector we're probing
@@ -1938,25 +1975,16 @@ struct edid *drm_do_get_edid(struct drm_connector 
*connector,
if (override)
return override;
 
-   if ((edid = kmalloc(EDID_LENGTH, GFP_KERNEL)) == NULL)
+   edid = (u8 *)drm_do_get_edid_blk0(get_edid_block, data,
+ >edid_corrupt,
+ >null_edid_counter);
+   if (IS_ERR_OR_NULL(edid)) {
+   if (IS_ERR(edid))
+   connector_bad_edid(connector, edid, 1);
return NULL;
-
-   /* base block fetch */
-   for (i = 0; i < 4; i++) {
-   if (get_edid_block(data, edid, 0, EDID_LENGTH))
-   goto out;
-   if (drm_edid_block_valid(edid, 0, false,
->edid_corrupt))
-   break;
-   if (i == 0 && drm_edid_is_zero(edid, EDID_LENGTH)) {
-   connector->null_edid_counter++;
-   goto carp;
-   }
}
-   if (i == 4)
-   goto carp;
 
-   /* if there's no extensions, we're done */
+   /* if there's no extensions or no connector, we're done */
valid_extensions = edid[0x7e];
if (valid_extensions == 0)
return (struct edid *)edid;
@@ -2010,8 +2038,6 @@ struct edid *drm_do_get_edid(struct drm_connector 
*connector,
 
return (struct edid *)edid;
 
-carp:
-   connector_bad_edid(connector, edid, 1);
 out:
kfree(edid);
return NULL;
-- 
2.33.0.259.gc128427fd7-goog