On 06/08/2024 14:52, Thomas Zimmermann wrote:
Convert DP501 support to struct drm_edid and its helpers. Simplifies
and modernizes the EDID handling.
The driver reads 4 bytes at once, but the overall read length is now
variable. Therefore update the EDID read loop to never return more than
the requested bytes.
Thanks for this patch.
I don't have a hardware to test, but I think it may break the EDID reading.
Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
---
drivers/gpu/drm/ast/ast_dp501.c | 92 ++++++++++++++++++++-------------
1 file changed, 55 insertions(+), 37 deletions(-)
diff --git a/drivers/gpu/drm/ast/ast_dp501.c b/drivers/gpu/drm/ast/ast_dp501.c
index 478efa226170..1c5a4902d4c2 100644
--- a/drivers/gpu/drm/ast/ast_dp501.c
+++ b/drivers/gpu/drm/ast/ast_dp501.c
@@ -318,32 +318,63 @@ static bool ast_dp501_is_connected(struct ast_device *ast)
return true;
}
-static bool ast_dp501_read_edid(struct drm_device *dev, u8 *ediddata)
+static int ast_dp512_read_edid_block(void *data, u8 *buf, unsigned int block, size_t len)
{
- struct ast_device *ast = to_ast_device(dev);
- u32 i, boot_address, offset, data;
- u32 *pEDIDidx;
+ struct ast_device *ast = data;
+ u32 i, boot_address, offset, ediddata;
- if (!ast_dp501_is_connected(ast))
- return false;
+ if (block > (512 / EDID_LENGTH))
+ return -EIO;
+
+ offset = AST_DP501_EDID_DATA + block * EDID_LENGTH;
if (ast->config_mode == ast_use_p2a) {
boot_address = get_fw_base(ast);
- /* Read EDID */
- offset = AST_DP501_EDID_DATA;
- for (i = 0; i < 128; i += 4) {
- data = ast_mindwm(ast, boot_address + offset + i);
- pEDIDidx = (u32 *)(ediddata + i);
- *pEDIDidx = data;
+ for (i = 0; i < len; i += 4) {
+ ediddata = ast_mindwm(ast, boot_address + offset + i);
I think "i" is always a multiple of 4, so the switch case is broken, and
will always go to case 0, so reading only 1 byte every 4 bytes ?
+
+ switch (i % 4) {
+ case 3:
+ *buf = (ediddata >> 24) & 0xff;
+ ++buf;
+ fallthrough;
+ case 2:
+ *buf = (ediddata >> 16) & 0xff;
+ ++buf;
+ fallthrough;
+ case 1:
+ *buf = (ediddata >> 8) & 0xff;
+ ++buf;
+ fallthrough;
+ case 0:
+ *buf = (ediddata) & 0xff;
+ ++buf;
+ break;
+ }
}
} else {
- /* Read EDID */
- offset = AST_DP501_EDID_DATA;
- for (i = 0; i < 128; i += 4) {
- data = readl(ast->dp501_fw_buf + offset + i);
- pEDIDidx = (u32 *)(ediddata + i);
- *pEDIDidx = data;
+ for (i = 0; i < len; i += 4) {
+ ediddata = readl(ast->dp501_fw_buf + offset + i);
+
+ switch (i % 4) {
+ case 3:
+ *buf = (ediddata >> 24) & 0xff;
+ ++buf;
+ fallthrough;
+ case 2:
+ *buf = (ediddata >> 16) & 0xff;
+ ++buf;
+ fallthrough;
+ case 1:
+ *buf = (ediddata >> 8) & 0xff;
+ ++buf;
+ fallthrough;
+ case 0:
+ *buf = (ediddata) & 0xff;
+ ++buf;
+ break;
+ }
}
}
@@ -511,29 +542,16 @@ static const struct drm_encoder_helper_funcs ast_dp501_encoder_helper_funcs = {
static int ast_dp501_connector_helper_get_modes(struct drm_connector *connector)
{
- void *edid;
- bool succ;
+ struct ast_device *ast = to_ast_device(connector->dev);
+ const struct drm_edid *drm_edid;
int count;
- edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
- if (!edid)
- goto err_drm_connector_update_edid_property;
-
- succ = ast_dp501_read_edid(connector->dev, edid);
- if (!succ)
- goto err_kfree;
-
- drm_connector_update_edid_property(connector, edid);
- count = drm_add_edid_modes(connector, edid);
- kfree(edid);
+ drm_edid = drm_edid_read_custom(connector, ast_dp512_read_edid_block, ast);
+ drm_edid_connector_update(connector, drm_edid);
+ count = drm_edid_connector_add_modes(connector);
+ drm_edid_free(drm_edid);
return count;
-
-err_kfree:
- kfree(edid);
-err_drm_connector_update_edid_property:
- drm_connector_update_edid_property(connector, NULL);
- return 0;
}
static int ast_dp501_connector_helper_detect_ctx(struct drm_connector *connector,
