[PATCH 6/7] drm/udl: Untangle .get_modes() and .detect_ctx()

Thomas Zimmermann tzimmermann at suse.de
Thu Apr 4 15:03:23 UTC 2024


Provide separate implementations of .get_modes() and .detect_ctx()
from struct drm_connector. Switch to struct drm_edid.

Udl's .detect() helper used to fetch the EDID from the adapter and the
.get_modes() helper provided display modes from the data. Switching to
the new helpers around struct drm_edid separates both from each other. The
.get_modes() helper now fetches the EDID by itself and the .detect_ctx()
helper only tests for its presence.

The patch does a number of things to implement this.

- Move udl_get_edid_block() to udl_edid.c and rename it to
udl_read_edid_block(). Then use the helper to implement probing in
udl_probe_edid() and reading in udl_edid_read(). Both udl helpers
are build on top of DRM helpers.

- Replace the existing code in .get_modes() and .detect() with udl's
new EDID helpers. The new code behaves like DRM's similar DDC-based
helpers. Instead of .detect(), udl now implements .detect_ctx().

- Remove the edid data from struct udl_connector. The field cached
the EDID data between calls to .detect() and .get_modes(), but is now
unused.

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
---
 drivers/gpu/drm/udl/Makefile      |  1 +
 drivers/gpu/drm/udl/udl_drv.h     |  2 -
 drivers/gpu/drm/udl/udl_edid.c    | 67 +++++++++++++++++++++++
 drivers/gpu/drm/udl/udl_edid.h    | 15 ++++++
 drivers/gpu/drm/udl/udl_modeset.c | 90 +++++++------------------------
 5 files changed, 102 insertions(+), 73 deletions(-)
 create mode 100644 drivers/gpu/drm/udl/udl_edid.c
 create mode 100644 drivers/gpu/drm/udl/udl_edid.h

diff --git a/drivers/gpu/drm/udl/Makefile b/drivers/gpu/drm/udl/Makefile
index 00690741db376..43d69a16af183 100644
--- a/drivers/gpu/drm/udl/Makefile
+++ b/drivers/gpu/drm/udl/Makefile
@@ -2,6 +2,7 @@
 
 udl-y := \
 	udl_drv.o \
+	udl_edid.o \
 	udl_main.o \
 	udl_modeset.o \
 	udl_transfer.o
diff --git a/drivers/gpu/drm/udl/udl_drv.h b/drivers/gpu/drm/udl/udl_drv.h
index 282ebd6c02fda..f112cfb270f31 100644
--- a/drivers/gpu/drm/udl/udl_drv.h
+++ b/drivers/gpu/drm/udl/udl_drv.h
@@ -51,8 +51,6 @@ struct urb_list {
 
 struct udl_connector {
 	struct drm_connector connector;
-	/* last udl_detect edid */
-	struct edid *edid;
 };
 
 static inline struct udl_connector *to_udl_connector(struct drm_connector *connector)
diff --git a/drivers/gpu/drm/udl/udl_edid.c b/drivers/gpu/drm/udl/udl_edid.c
new file mode 100644
index 0000000000000..caa9641996e92
--- /dev/null
+++ b/drivers/gpu/drm/udl/udl_edid.c
@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <drm/drm_drv.h>
+#include <drm/drm_edid.h>
+
+#include "udl_drv.h"
+#include "udl_edid.h"
+
+static int udl_read_edid_block(void *data, u8 *buf, unsigned int block, size_t len)
+{
+	struct udl_device *udl = data;
+	struct drm_device *dev = &udl->drm;
+	struct usb_device *udev = udl_to_usb_device(udl);
+	u8 *read_buff;
+	int idx, ret;
+	size_t i;
+
+	read_buff = kmalloc(2, GFP_KERNEL);
+	if (!read_buff)
+		return -ENOMEM;
+
+	if (!drm_dev_enter(dev, &idx)) {
+		ret = -ENODEV;
+		goto err_kfree;
+	}
+
+	for (i = 0; i < len; i++) {
+		int bval = (i + block * EDID_LENGTH) << 8;
+
+		ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
+				      0x02, (0x80 | (0x02 << 5)), bval,
+				      0xA1, read_buff, 2, USB_CTRL_GET_TIMEOUT);
+		if (ret < 0) {
+			drm_err(dev, "Read EDID byte %zu failed err %x\n", i, ret);
+			goto err_drm_dev_exit;
+		} else if (ret < 1) {
+			ret = -EIO;
+			drm_err(dev, "Read EDID byte %zu failed\n", i);
+			goto err_drm_dev_exit;
+		}
+
+		buf[i] = read_buff[1];
+	}
+
+	drm_dev_exit(idx);
+	kfree(read_buff);
+
+	return 0;
+
+err_drm_dev_exit:
+	drm_dev_exit(idx);
+err_kfree:
+	kfree(read_buff);
+	return ret;
+}
+
+bool udl_probe_edid(struct udl_device *udl)
+{
+	return drm_edid_probe_custom(udl_read_edid_block, udl, true);
+}
+
+const struct drm_edid *udl_edid_read(struct drm_connector *connector)
+{
+	struct udl_device *udl = to_udl(connector->dev);
+
+	return drm_edid_read_custom(connector, udl_read_edid_block, udl);
+}
diff --git a/drivers/gpu/drm/udl/udl_edid.h b/drivers/gpu/drm/udl/udl_edid.h
new file mode 100644
index 0000000000000..fe15ff3752b7d
--- /dev/null
+++ b/drivers/gpu/drm/udl/udl_edid.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef UDL_EDID_H
+#define UDL_EDID_H
+
+#include <linux/types.h>
+
+struct drm_connector;
+struct drm_edid;
+struct udl_device;
+
+bool udl_probe_edid(struct udl_device *udl);
+const struct drm_edid *udl_edid_read(struct drm_connector *connector);
+
+#endif
diff --git a/drivers/gpu/drm/udl/udl_modeset.c b/drivers/gpu/drm/udl/udl_modeset.c
index 3df9fc38388b4..4236ce57f5945 100644
--- a/drivers/gpu/drm/udl/udl_modeset.c
+++ b/drivers/gpu/drm/udl/udl_modeset.c
@@ -25,6 +25,7 @@
 #include <drm/drm_vblank.h>
 
 #include "udl_drv.h"
+#include "udl_edid.h"
 #include "udl_proto.h"
 
 /*
@@ -415,97 +416,44 @@ static const struct drm_encoder_funcs udl_encoder_funcs = {
 
 static int udl_connector_helper_get_modes(struct drm_connector *connector)
 {
-	struct udl_connector *udl_connector = to_udl_connector(connector);
+	const struct drm_edid *drm_edid;
+	int count;
 
-	drm_connector_update_edid_property(connector, udl_connector->edid);
-	if (udl_connector->edid)
-		return drm_add_edid_modes(connector, udl_connector->edid);
+	drm_edid = udl_edid_read(connector);
+	drm_edid_connector_update(connector, drm_edid);
+	count = drm_edid_connector_add_modes(connector);
+	drm_edid_free(drm_edid);
 
-	return 0;
+	return count;
 }
 
-static const struct drm_connector_helper_funcs udl_connector_helper_funcs = {
-	.get_modes = udl_connector_helper_get_modes,
-};
-
-static int udl_get_edid_block(void *data, u8 *buf, unsigned int block, size_t len)
+static int udl_connector_helper_detect_ctx(struct drm_connector *connector,
+					   struct drm_modeset_acquire_ctx *ctx,
+					   bool force)
 {
-	struct udl_device *udl = data;
-	struct drm_device *dev = &udl->drm;
-	struct usb_device *udev = udl_to_usb_device(udl);
-	u8 *read_buff;
-	int idx, ret;
-	size_t i;
-
-	read_buff = kmalloc(2, GFP_KERNEL);
-	if (!read_buff)
-		return -ENOMEM;
+	struct udl_device *udl = to_udl(connector->dev);
 
-	if (!drm_dev_enter(dev, &idx)) {
-		ret = -ENODEV;
-		goto err_kfree;
-	}
-
-	for (i = 0; i < len; i++) {
-		int bval = (i + block * EDID_LENGTH) << 8;
-
-		ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
-				      0x02, (0x80 | (0x02 << 5)), bval,
-				      0xA1, read_buff, 2, USB_CTRL_GET_TIMEOUT);
-		if (ret < 0) {
-			drm_err(dev, "Read EDID byte %zu failed err %x\n", i, ret);
-			goto err_drm_dev_exit;
-		} else if (ret < 1) {
-			ret = -EIO;
-			drm_err(dev, "Read EDID byte %zu failed\n", i);
-			goto err_drm_dev_exit;
-		}
-
-		buf[i] = read_buff[1];
-	}
+	if (udl_probe_edid(udl))
+		return connector_status_connected;
 
-	drm_dev_exit(idx);
-	kfree(read_buff);
-
-	return 0;
-
-err_drm_dev_exit:
-	drm_dev_exit(idx);
-err_kfree:
-	kfree(read_buff);
-	return ret;
+	return connector_status_disconnected;
 }
 
-static enum drm_connector_status udl_connector_detect(struct drm_connector *connector, bool force)
-{
-	struct drm_device *dev = connector->dev;
-	struct udl_device *udl = to_udl(dev);
-	struct udl_connector *udl_connector = to_udl_connector(connector);
-	enum drm_connector_status status = connector_status_disconnected;
-
-	/* cleanup previous EDID */
-	kfree(udl_connector->edid);
-	udl_connector->edid = NULL;
-
-	udl_connector->edid = drm_do_get_edid(connector, udl_get_edid_block, udl);
-	if (udl_connector->edid)
-		status = connector_status_connected;
-
-	return status;
-}
+static const struct drm_connector_helper_funcs udl_connector_helper_funcs = {
+	.get_modes = udl_connector_helper_get_modes,
+	.detect_ctx = udl_connector_helper_detect_ctx,
+};
 
 static void udl_connector_destroy(struct drm_connector *connector)
 {
 	struct udl_connector *udl_connector = to_udl_connector(connector);
 
 	drm_connector_cleanup(connector);
-	kfree(udl_connector->edid);
 	kfree(udl_connector);
 }
 
 static const struct drm_connector_funcs udl_connector_funcs = {
 	.reset = drm_atomic_helper_connector_reset,
-	.detect = udl_connector_detect,
 	.fill_modes = drm_helper_probe_single_connector_modes,
 	.destroy = udl_connector_destroy,
 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
-- 
2.44.0



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