We have an abstraction for the EDID base block read, yet duplicating the
retries and error handling for extension block reads. Introduce a more
generic EDID block read helper.
Switch to the helper piecemeal, starting with drm_edid_get_panel_id(),
which doesn't need or have access to the connector anyway.
The subtle change is switching from drm_edid_block_valid() to
edid_block_check(). We also status print once, not for every attempt.
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
---
drivers/gpu/drm/drm_edid.c | 58 +++++++++++++++++++++++++++++++++-----
1 file changed, 51 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 926ffe5cd97e..162f0a959376 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -1670,6 +1670,7 @@ EXPORT_SYMBOL(drm_edid_are_equal);
enum edid_block_status {
EDID_BLOCK_OK = 0,
+ EDID_BLOCK_READ_FAIL,
EDID_BLOCK_NULL,
EDID_BLOCK_ZERO,
EDID_BLOCK_HEADER_CORRUPT,
@@ -1736,6 +1737,9 @@ static void edid_block_status_print(enum edid_block_status status,
switch (status) {
case EDID_BLOCK_OK:
break;
+ case EDID_BLOCK_READ_FAIL:
+ pr_debug("EDID block %d read failed\n", block_num);
+ break;
case EDID_BLOCK_NULL:
pr_debug("EDID block %d pointer is NULL\n", block_num);
break;
@@ -2039,6 +2043,39 @@ EXPORT_SYMBOL(drm_add_override_edid_modes);
typedef int read_block_fn(void *context, u8 *buf, unsigned int block, size_t len);
+static enum edid_block_status edid_block_read(void *block, unsigned int block_num,
+ read_block_fn read_block,
+ void *context)
+{
+ enum edid_block_status status;
+ bool is_base_block = block_num == 0;
+ int try;
+
+ for (try = 0; try < 4; try++) {
+ if (read_block(context, block, block_num, EDID_LENGTH))
+ return EDID_BLOCK_READ_FAIL;
+
+ status = edid_block_check(block, is_base_block);
+ if (status == EDID_BLOCK_HEADER_REPAIR) {
+ edid_header_fix(block);
+
+ /* Retry with fixed header, update status if that worked. */
+ status = edid_block_check(block, is_base_block);
+ if (status == EDID_BLOCK_OK)
+ status = EDID_BLOCK_HEADER_FIXED;
+ }
+
+ if (edid_block_status_valid(status, edid_block_tag(block)))
+ break;
+
+ /* Fail early for unrepairable base block all zeros. */
+ if (try == 0 && is_base_block && status == EDID_BLOCK_ZERO)
+ break;
+ }
+
+ return status;
+}
+
static struct edid *drm_do_get_edid_base_block(struct drm_connector *connector,
read_block_fn read_block,
void *context)
@@ -2237,20 +2274,27 @@ static u32 edid_extract_panel_id(const struct edid *edid)
u32 drm_edid_get_panel_id(struct i2c_adapter *adapter)
{
- const struct edid *edid;
- u32 panel_id;
-
- edid = drm_do_get_edid_base_block(NULL, drm_do_probe_ddc_edid, adapter);
+ enum edid_block_status status;
+ void *base_block;
+ u32 panel_id = 0;
/*
* There are no manufacturer IDs of 0, so if there is a problem reading
* the EDID then we'll just return 0.
*/
- if (!edid)
+
+ base_block = kmalloc(EDID_LENGTH, GFP_KERNEL);
+ if (!base_block)
return 0;
- panel_id = edid_extract_panel_id(edid);
- kfree(edid);
+ status = edid_block_read(base_block, 0, drm_do_probe_ddc_edid, adapter);
+
+ edid_block_status_print(status, base_block, 0);
+
+ if (edid_block_status_valid(status, edid_block_tag(base_block)))
+ panel_id = edid_extract_panel_id(base_block);
+
+ kfree(base_block);
return panel_id;
}
--
2.30.2
