Re: [PATCH v2 1/3] drm_edid: Support getting EDID through ddc without connector
On Wed, Feb 28, 2024 at 4:21 PM Doug Anderson wrote:
>
> Hi,
>
> On Tue, Feb 27, 2024 at 5:11 PM Hsin-Yi Wang wrote:
> >
> > Some panels are interested in the EDID during early probe when connector
> > is still unknown.
> >
> > Add a function drm_get_edid_no_connector() to get edid without connector.
> > No functional change for existing usage.
> >
> > Signed-off-by: Hsin-Yi Wang
> > ---
> > v1->v2:
> > add a function to return the entire edid without updating connector.
> > ---
> > drivers/gpu/drm/drm_edid.c | 45 --
> > include/drm/drm_edid.h | 1 +
> > 2 files changed, 34 insertions(+), 12 deletions(-)
>
> I'll respond in the discussion in v1 too, but overall I'm not a fan of
> reading the whole EDID twice at bootup. Personally I'd love to see us
> to back to just reading the base block like in v1, but I guess we can
> see what Jani and others say.
>
>
> > @@ -2385,18 +2385,20 @@ static struct edid *_drm_do_get_edid(struct
> > drm_connector *connector,
> > if (status == EDID_BLOCK_READ_FAIL)
> > goto fail;
> >
> > - /* FIXME: Clarify what a corrupt EDID actually means. */
> > - if (status == EDID_BLOCK_OK || status == EDID_BLOCK_VERSION)
> > - connector->edid_corrupt = false;
> > - else
> > - connector->edid_corrupt = true;
> > + if (connector) {
> > + /* FIXME: Clarify what a corrupt EDID actually means. */
> > + if (status == EDID_BLOCK_OK || status == EDID_BLOCK_VERSION)
> > + connector->edid_corrupt = false;
> > + else
> > + connector->edid_corrupt = true;
> >
> > - if (!edid_block_status_valid(status, edid_block_tag(edid))) {
> > - if (status == EDID_BLOCK_ZERO)
> > - connector->null_edid_counter++;
> > + if (!edid_block_status_valid(status, edid_block_tag(edid)))
> > {
> > + if (status == EDID_BLOCK_ZERO)
> > + connector->null_edid_counter++;
> >
> > - connector_bad_edid(connector, edid, 1);
> > - goto fail;
> > + connector_bad_edid(connector, edid, 1);
> > + goto fail;
>
> This "goto fail" is now only run "if (connector)" which means that
> you're not properly checking if the EDID is valid when "connector ==
> NULL", right? That seems like a bug unless I missed something...
We can't check with connector_bad_edid() since there's no connector.
But we still check with edid_block_read() status, similar to what the
original drm_edid_get_panel_id() checks.
Re: [PATCH v2 1/3] drm_edid: Support getting EDID through ddc without connector
Hi,
On Tue, Feb 27, 2024 at 5:11 PM Hsin-Yi Wang wrote:
>
> Some panels are interested in the EDID during early probe when connector
> is still unknown.
>
> Add a function drm_get_edid_no_connector() to get edid without connector.
> No functional change for existing usage.
>
> Signed-off-by: Hsin-Yi Wang
> ---
> v1->v2:
> add a function to return the entire edid without updating connector.
> ---
> drivers/gpu/drm/drm_edid.c | 45 --
> include/drm/drm_edid.h | 1 +
> 2 files changed, 34 insertions(+), 12 deletions(-)
I'll respond in the discussion in v1 too, but overall I'm not a fan of
reading the whole EDID twice at bootup. Personally I'd love to see us
to back to just reading the base block like in v1, but I guess we can
see what Jani and others say.
> @@ -2385,18 +2385,20 @@ static struct edid *_drm_do_get_edid(struct
> drm_connector *connector,
> if (status == EDID_BLOCK_READ_FAIL)
> goto fail;
>
> - /* FIXME: Clarify what a corrupt EDID actually means. */
> - if (status == EDID_BLOCK_OK || status == EDID_BLOCK_VERSION)
> - connector->edid_corrupt = false;
> - else
> - connector->edid_corrupt = true;
> + if (connector) {
> + /* FIXME: Clarify what a corrupt EDID actually means. */
> + if (status == EDID_BLOCK_OK || status == EDID_BLOCK_VERSION)
> + connector->edid_corrupt = false;
> + else
> + connector->edid_corrupt = true;
>
> - if (!edid_block_status_valid(status, edid_block_tag(edid))) {
> - if (status == EDID_BLOCK_ZERO)
> - connector->null_edid_counter++;
> + if (!edid_block_status_valid(status, edid_block_tag(edid))) {
> + if (status == EDID_BLOCK_ZERO)
> + connector->null_edid_counter++;
>
> - connector_bad_edid(connector, edid, 1);
> - goto fail;
> + connector_bad_edid(connector, edid, 1);
> + goto fail;
This "goto fail" is now only run "if (connector)" which means that
you're not properly checking if the EDID is valid when "connector ==
NULL", right? That seems like a bug unless I missed something...
Re: [PATCH v2 1/3] drm_edid: Support getting EDID through ddc without connector
On Tue, Feb 27, 2024 at 5:11 PM Hsin-Yi Wang wrote:
>
> Some panels are interested in the EDID during early probe when connector
> is still unknown.
>
> Add a function drm_get_edid_no_connector() to get edid without connector.
> No functional change for existing usage.
>
> Signed-off-by: Hsin-Yi Wang
> ---
> v1->v2:
> add a function to return the entire edid without updating connector.
> ---
> drivers/gpu/drm/drm_edid.c | 45 --
> include/drm/drm_edid.h | 1 +
> 2 files changed, 34 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 1ad94473e400..15b97c8ed993 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -2364,7 +2364,7 @@ static struct edid *_drm_do_get_edid(struct
> drm_connector *connector,
> struct edid *edid, *new;
> size_t alloc_size = EDID_LENGTH;
>
> - override = drm_edid_override_get(connector);
> + override = connector ? drm_edid_override_get(connector) : false;
typo: should be NULL here. I'll update in the next version with other comments.
> if (override) {
> alloc_size = override->size;
> edid = kmemdup(override->edid, alloc_size, GFP_KERNEL);
> @@ -2385,18 +2385,20 @@ static struct edid *_drm_do_get_edid(struct
> drm_connector *connector,
> if (status == EDID_BLOCK_READ_FAIL)
> goto fail;
>
> - /* FIXME: Clarify what a corrupt EDID actually means. */
> - if (status == EDID_BLOCK_OK || status == EDID_BLOCK_VERSION)
> - connector->edid_corrupt = false;
> - else
> - connector->edid_corrupt = true;
> + if (connector) {
> + /* FIXME: Clarify what a corrupt EDID actually means. */
> + if (status == EDID_BLOCK_OK || status == EDID_BLOCK_VERSION)
> + connector->edid_corrupt = false;
> + else
> + connector->edid_corrupt = true;
>
> - if (!edid_block_status_valid(status, edid_block_tag(edid))) {
> - if (status == EDID_BLOCK_ZERO)
> - connector->null_edid_counter++;
> + if (!edid_block_status_valid(status, edid_block_tag(edid))) {
> + if (status == EDID_BLOCK_ZERO)
> + connector->null_edid_counter++;
>
> - connector_bad_edid(connector, edid, 1);
> - goto fail;
> + connector_bad_edid(connector, edid, 1);
> + goto fail;
> + }
> }
>
> if (!edid_extension_block_count(edid))
> @@ -2444,7 +2446,8 @@ static struct edid *_drm_do_get_edid(struct
> drm_connector *connector,
> }
>
> if (invalid_blocks) {
> - connector_bad_edid(connector, edid, num_blocks);
> + if (connector)
> + connector_bad_edid(connector, edid, num_blocks);
>
> edid = edid_filter_invalid_blocks(edid, _size);
> }
> @@ -2637,6 +2640,24 @@ struct edid *drm_get_edid(struct drm_connector
> *connector,
> }
> EXPORT_SYMBOL(drm_get_edid);
>
> +/**
> + * drm_get_edid_no_connector - get EDID data without updating connector
> status
> + * @adapter: I2C adapter to use for DDC
> + *
> + * Similar to drm_edid_read_ddc(), but not checking any connector status. Use
> + * this function to get EDID when connector is still unknown.
> + *
> + * Return: Pointer to valid EDID or NULL if we couldn't find any.
> + */
> +struct edid *drm_get_edid_no_connector(struct i2c_adapter *adapter)
> +{
> + if (!drm_probe_ddc(adapter))
> + return NULL;
> +
> + return _drm_do_get_edid(NULL, drm_do_probe_ddc_edid, adapter, NULL);
> +}
> +EXPORT_SYMBOL(drm_get_edid_no_connector);
> +
> /**
> * drm_edid_read_custom - Read EDID data using given EDID block read function
> * @connector: Connector to use
> diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
> index 70ae6c290bdc..80c9e32ff80e 100644
> --- a/include/drm/drm_edid.h
> +++ b/include/drm/drm_edid.h
> @@ -565,6 +565,7 @@ struct edid *drm_do_get_edid(struct drm_connector
> *connector,
> void *data);
> struct edid *drm_get_edid(struct drm_connector *connector,
> struct i2c_adapter *adapter);
> +struct edid *drm_get_edid_no_connector(struct i2c_adapter *adapter);
> u32 drm_edid_get_panel_id(struct i2c_adapter *adapter);
> struct edid *drm_get_edid_switcheroo(struct drm_connector *connector,
> struct i2c_adapter *adapter);
> --
> 2.44.0.rc1.240.g4c46232300-goog
>
[PATCH v2 1/3] drm_edid: Support getting EDID through ddc without connector
Some panels are interested in the EDID during early probe when connector
is still unknown.
Add a function drm_get_edid_no_connector() to get edid without connector.
No functional change for existing usage.
Signed-off-by: Hsin-Yi Wang
---
v1->v2:
add a function to return the entire edid without updating connector.
---
drivers/gpu/drm/drm_edid.c | 45 --
include/drm/drm_edid.h | 1 +
2 files changed, 34 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 1ad94473e400..15b97c8ed993 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -2364,7 +2364,7 @@ static struct edid *_drm_do_get_edid(struct drm_connector
*connector,
struct edid *edid, *new;
size_t alloc_size = EDID_LENGTH;
- override = drm_edid_override_get(connector);
+ override = connector ? drm_edid_override_get(connector) : false;
if (override) {
alloc_size = override->size;
edid = kmemdup(override->edid, alloc_size, GFP_KERNEL);
@@ -2385,18 +2385,20 @@ static struct edid *_drm_do_get_edid(struct
drm_connector *connector,
if (status == EDID_BLOCK_READ_FAIL)
goto fail;
- /* FIXME: Clarify what a corrupt EDID actually means. */
- if (status == EDID_BLOCK_OK || status == EDID_BLOCK_VERSION)
- connector->edid_corrupt = false;
- else
- connector->edid_corrupt = true;
+ if (connector) {
+ /* FIXME: Clarify what a corrupt EDID actually means. */
+ if (status == EDID_BLOCK_OK || status == EDID_BLOCK_VERSION)
+ connector->edid_corrupt = false;
+ else
+ connector->edid_corrupt = true;
- if (!edid_block_status_valid(status, edid_block_tag(edid))) {
- if (status == EDID_BLOCK_ZERO)
- connector->null_edid_counter++;
+ if (!edid_block_status_valid(status, edid_block_tag(edid))) {
+ if (status == EDID_BLOCK_ZERO)
+ connector->null_edid_counter++;
- connector_bad_edid(connector, edid, 1);
- goto fail;
+ connector_bad_edid(connector, edid, 1);
+ goto fail;
+ }
}
if (!edid_extension_block_count(edid))
@@ -2444,7 +2446,8 @@ static struct edid *_drm_do_get_edid(struct drm_connector
*connector,
}
if (invalid_blocks) {
- connector_bad_edid(connector, edid, num_blocks);
+ if (connector)
+ connector_bad_edid(connector, edid, num_blocks);
edid = edid_filter_invalid_blocks(edid, _size);
}
@@ -2637,6 +2640,24 @@ struct edid *drm_get_edid(struct drm_connector
*connector,
}
EXPORT_SYMBOL(drm_get_edid);
+/**
+ * drm_get_edid_no_connector - get EDID data without updating connector status
+ * @adapter: I2C adapter to use for DDC
+ *
+ * Similar to drm_edid_read_ddc(), but not checking any connector status. Use
+ * this function to get EDID when connector is still unknown.
+ *
+ * Return: Pointer to valid EDID or NULL if we couldn't find any.
+ */
+struct edid *drm_get_edid_no_connector(struct i2c_adapter *adapter)
+{
+ if (!drm_probe_ddc(adapter))
+ return NULL;
+
+ return _drm_do_get_edid(NULL, drm_do_probe_ddc_edid, adapter, NULL);
+}
+EXPORT_SYMBOL(drm_get_edid_no_connector);
+
/**
* drm_edid_read_custom - Read EDID data using given EDID block read function
* @connector: Connector to use
diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
index 70ae6c290bdc..80c9e32ff80e 100644
--- a/include/drm/drm_edid.h
+++ b/include/drm/drm_edid.h
@@ -565,6 +565,7 @@ struct edid *drm_do_get_edid(struct drm_connector
*connector,
void *data);
struct edid *drm_get_edid(struct drm_connector *connector,
struct i2c_adapter *adapter);
+struct edid *drm_get_edid_no_connector(struct i2c_adapter *adapter);
u32 drm_edid_get_panel_id(struct i2c_adapter *adapter);
struct edid *drm_get_edid_switcheroo(struct drm_connector *connector,
struct i2c_adapter *adapter);
--
2.44.0.rc1.240.g4c46232300-goog
