diff mbox series

[v6,2/5] drm/edid: Add a function to match EDID with identity

Message ID 20240307230653.1807557-3-hsinyi@chromium.org (mailing list archive)
State New, archived
Headers show
Series Match panel with identity | expand

Commit Message

Hsin-Yi Wang March 7, 2024, 10:57 p.m. UTC
Create a type drm_edid_ident as the identity of an EDID. Currently it
contains panel id and monitor name.

Create a function that can match a given EDID and an identity:
1. Reject if the panel id doesn't match.
2. If name is not null in identity, try to match it in the detailed timing
   blocks. Note that some panel vendors put the monitor name after
   EDID_DETAIL_MONITOR_STRING.

Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
---
v5->v6: finalize the trailing white space and/or NUL decision:
Allow only white space before \n.
---
 drivers/gpu/drm/drm_edid.c | 65 ++++++++++++++++++++++++++++++++++++++
 include/drm/drm_edid.h     |  9 ++++++
 2 files changed, 74 insertions(+)

Comments

Doug Anderson March 8, 2024, 12:04 a.m. UTC | #1
Hi,

On Thu, Mar 7, 2024 at 3:07 PM Hsin-Yi Wang <hsinyi@chromium.org> wrote:
>
> Create a type drm_edid_ident as the identity of an EDID. Currently it
> contains panel id and monitor name.
>
> Create a function that can match a given EDID and an identity:
> 1. Reject if the panel id doesn't match.
> 2. If name is not null in identity, try to match it in the detailed timing
>    blocks. Note that some panel vendors put the monitor name after
>    EDID_DETAIL_MONITOR_STRING.
>
> Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
> ---
> v5->v6: finalize the trailing white space and/or NUL decision:
> Allow only white space before \n.
> ---
>  drivers/gpu/drm/drm_edid.c | 65 ++++++++++++++++++++++++++++++++++++++
>  include/drm/drm_edid.h     |  9 ++++++
>  2 files changed, 74 insertions(+)

Reviewed-by: Douglas Anderson <dianders@chromium.org>
Jani Nikula March 8, 2024, 8:07 a.m. UTC | #2
On Thu, 07 Mar 2024, Hsin-Yi Wang <hsinyi@chromium.org> wrote:
> Create a type drm_edid_ident as the identity of an EDID. Currently it
> contains panel id and monitor name.
>
> Create a function that can match a given EDID and an identity:
> 1. Reject if the panel id doesn't match.
> 2. If name is not null in identity, try to match it in the detailed timing
>    blocks. Note that some panel vendors put the monitor name after
>    EDID_DETAIL_MONITOR_STRING.
>
> Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>

Reviewed-by: Jani Nikula <jani.nikula@intel.com>

The series seems good to go. Thanks Hsin-Yi and Douglas for the
constructive collaboration! I believe the end result is better now.

Thanks,
Jani.
Doug Anderson March 8, 2024, 2:38 p.m. UTC | #3
Hi,

On Fri, Mar 8, 2024 at 12:07 AM Jani Nikula <jani.nikula@linux.intel.com> wrote:
>
> On Thu, 07 Mar 2024, Hsin-Yi Wang <hsinyi@chromium.org> wrote:
> > Create a type drm_edid_ident as the identity of an EDID. Currently it
> > contains panel id and monitor name.
> >
> > Create a function that can match a given EDID and an identity:
> > 1. Reject if the panel id doesn't match.
> > 2. If name is not null in identity, try to match it in the detailed timing
> >    blocks. Note that some panel vendors put the monitor name after
> >    EDID_DETAIL_MONITOR_STRING.
> >
> > Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
>
> Reviewed-by: Jani Nikula <jani.nikula@intel.com>
>
> The series seems good to go. Thanks Hsin-Yi and Douglas for the
> constructive collaboration! I believe the end result is better now.

Thanks! Unless there are any objections in the meantime, I'll plan to
apply the whole series to drm-misc-next late next week.

-Doug
Hsin-Yi Wang March 8, 2024, 7:26 p.m. UTC | #4
On Fri, Mar 8, 2024 at 12:07 AM Jani Nikula <jani.nikula@linux.intel.com> wrote:
>
> On Thu, 07 Mar 2024, Hsin-Yi Wang <hsinyi@chromium.org> wrote:
> > Create a type drm_edid_ident as the identity of an EDID. Currently it
> > contains panel id and monitor name.
> >
> > Create a function that can match a given EDID and an identity:
> > 1. Reject if the panel id doesn't match.
> > 2. If name is not null in identity, try to match it in the detailed timing
> >    blocks. Note that some panel vendors put the monitor name after
> >    EDID_DETAIL_MONITOR_STRING.
> >
> > Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
>
> Reviewed-by: Jani Nikula <jani.nikula@intel.com>
>
> The series seems good to go. Thanks Hsin-Yi and Douglas for the
> constructive collaboration! I believe the end result is better now.
>

Thanks for everyone's suggestions to make it better.

> Thanks,
> Jani.
>
> --
> Jani Nikula, Intel
diff mbox series

Patch

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 284255a0315e..58fe35058181 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -100,6 +100,11 @@  struct detailed_mode_closure {
 	int modes;
 };
 
+struct drm_edid_match_closure {
+	const struct drm_edid_ident *ident;
+	bool matched;
+};
+
 #define LEVEL_DMT	0
 #define LEVEL_GTF	1
 #define LEVEL_GTF2	2
@@ -5408,6 +5413,66 @@  drm_parse_hdmi_vsdb_audio(struct drm_connector *connector, const u8 *db)
 		    connector->audio_latency[0], connector->audio_latency[1]);
 }
 
+static void
+match_identity(const struct detailed_timing *timing, void *data)
+{
+	struct drm_edid_match_closure *closure = data;
+	unsigned int i;
+	const char *name = closure->ident->name;
+	unsigned int name_len = strlen(name);
+	const char *desc = timing->data.other_data.data.str.str;
+	unsigned int desc_len = ARRAY_SIZE(timing->data.other_data.data.str.str);
+
+	if (name_len > desc_len ||
+	    !(is_display_descriptor(timing, EDID_DETAIL_MONITOR_NAME) ||
+	      is_display_descriptor(timing, EDID_DETAIL_MONITOR_STRING)))
+		return;
+
+	if (strncmp(name, desc, name_len))
+		return;
+
+	for (i = name_len; i < desc_len; i++) {
+		if (desc[i] == '\n')
+			break;
+		/* Allow white space before EDID string terminator. */
+		if (!isspace(desc[i]))
+			return;
+	}
+
+	closure->matched = true;
+}
+
+/**
+ * drm_edid_match - match drm_edid with given identity
+ * @drm_edid: EDID
+ * @ident: the EDID identity to match with
+ *
+ * Check if the EDID matches with the given identity.
+ *
+ * Return: True if the given identity matched with EDID, false otherwise.
+ */
+bool drm_edid_match(const struct drm_edid *drm_edid,
+		    const struct drm_edid_ident *ident)
+{
+	if (!drm_edid || drm_edid_get_panel_id(drm_edid) != ident->panel_id)
+		return false;
+
+	/* Match with name only if it's not NULL. */
+	if (ident->name) {
+		struct drm_edid_match_closure closure = {
+			.ident = ident,
+			.matched = false,
+		};
+
+		drm_for_each_detailed_block(drm_edid, match_identity, &closure);
+
+		return closure.matched;
+	}
+
+	return true;
+}
+EXPORT_SYMBOL(drm_edid_match);
+
 static void
 monitor_name(const struct detailed_timing *timing, void *data)
 {
diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
index 8b233865b085..5e3fc8c83a31 100644
--- a/include/drm/drm_edid.h
+++ b/include/drm/drm_edid.h
@@ -367,6 +367,13 @@  struct edid {
 	u8 checksum;
 } __attribute__((packed));
 
+/* EDID matching */
+struct drm_edid_ident {
+	/* ID encoded by drm_edid_encode_panel_id() */
+	u32 panel_id;
+	const char *name;
+};
+
 #define EDID_PRODUCT_ID(e) ((e)->prod_code[0] | ((e)->prod_code[1] << 8))
 
 /* Short Audio Descriptor */
@@ -567,6 +574,8 @@  struct edid *drm_get_edid(struct drm_connector *connector,
 			  struct i2c_adapter *adapter);
 const struct drm_edid *drm_edid_read_base_block(struct i2c_adapter *adapter);
 u32 drm_edid_get_panel_id(const struct drm_edid *drm_edid);
+bool drm_edid_match(const struct drm_edid *drm_edid,
+		    const struct drm_edid_ident *ident);
 struct edid *drm_get_edid_switcheroo(struct drm_connector *connector,
 				     struct i2c_adapter *adapter);
 struct edid *drm_edid_duplicate(const struct edid *edid);