diff mbox series

[v2] drm/bochs: add edid support.

Message ID 20181005120934.21959-1-kraxel@redhat.com (mailing list archive)
State New, archived
Headers show
Series [v2] drm/bochs: add edid support. | expand

Commit Message

Gerd Hoffmann Oct. 5, 2018, 12:09 p.m. UTC
Recent qemu (latest master branch, upcoming 3.1 release) got support
for EDID data.  This patch adds guest driver support.

EDID support in qemu is not (yet) enabled by default, so please use
'qemu -device VGA,edid=on' for testing.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 drivers/gpu/drm/bochs/bochs.h     |  1 +
 drivers/gpu/drm/bochs/bochs_hw.c  | 38 ++++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/bochs/bochs_kms.c | 18 +++++++++++++++---
 3 files changed, 54 insertions(+), 3 deletions(-)

Comments

Dave Airlie Oct. 18, 2018, 1:15 a.m. UTC | #1
On Fri, 5 Oct 2018 at 22:10, Gerd Hoffmann <kraxel@redhat.com> wrote:
>
> Recent qemu (latest master branch, upcoming 3.1 release) got support
> for EDID data.  This patch adds guest driver support.
>
> EDID support in qemu is not (yet) enabled by default, so please use
> 'qemu -device VGA,edid=on' for testing.

The EDID never changes after boot? Is there plans to let it?
>
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>  drivers/gpu/drm/bochs/bochs.h     |  1 +
>  drivers/gpu/drm/bochs/bochs_hw.c  | 38 ++++++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/bochs/bochs_kms.c | 18 +++++++++++++++---
>  3 files changed, 54 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/bochs/bochs.h b/drivers/gpu/drm/bochs/bochs.h
> index e7a69077e4..06b8166efa 100644
> --- a/drivers/gpu/drm/bochs/bochs.h
> +++ b/drivers/gpu/drm/bochs/bochs.h
> @@ -66,6 +66,7 @@ struct bochs_device {
>         u16 yres_virtual;
>         u32 stride;
>         u32 bpp;
> +       struct edid *edid;
>
>         /* drm */
>         struct drm_device  *dev;
> diff --git a/drivers/gpu/drm/bochs/bochs_hw.c b/drivers/gpu/drm/bochs/bochs_hw.c
> index cacff73a64..6ce4cdac38 100644
> --- a/drivers/gpu/drm/bochs/bochs_hw.c
> +++ b/drivers/gpu/drm/bochs/bochs_hw.c
> @@ -69,6 +69,41 @@ static void bochs_hw_set_little_endian(struct bochs_device *bochs)
>  #define bochs_hw_set_native_endian(_b) bochs_hw_set_little_endian(_b)
>  #endif
>
> +static int bochs_load_edid(struct bochs_device *bochs)
> +{
> +       uint8_t *blob;
> +       size_t i, len;
> +       uint8_t num_exts;
> +
> +       if (!bochs->mmio)
> +               return -1;
> +
> +       if ((readb(bochs->mmio+0) != 0x00 ||
> +            readb(bochs->mmio+1) != 0xff))
> +               return -1;
> +
> +       num_exts = readb(bochs->mmio + 126);
> +       len = EDID_LENGTH * (1 + num_exts);
> +       if (len > 0x400 /* vga register offset */)
> +               return -1;
> +
> +       kfree(bochs->edid);
> +       bochs->edid = kmalloc(len, GFP_KERNEL);

Don't you need to free it somewhere?

Dave.
Gerd Hoffmann Oct. 18, 2018, 5:11 a.m. UTC | #2
Hi,

> > Recent qemu (latest master branch, upcoming 3.1 release) got support
> > for EDID data.  This patch adds guest driver support.
> >
> > EDID support in qemu is not (yet) enabled by default, so please use
> > 'qemu -device VGA,edid=on' for testing.
> 
> The EDID never changes after boot?

Right now it doesn't.

> Is there plans to let it?

Needs more virtual hardware changes, the stdvga has no support for
interrupts, so qemu can't signal an edid update to the guest.

So not not sure yet what to do about it.  Maybe add it later (but it's
not high priority).  Maybe simply recommend to use virtio-gpu instead.

> > +       kfree(bochs->edid);
> > +       bochs->edid = kmalloc(len, GFP_KERNEL);
> 
> Don't you need to free it somewhere?

Oh, yes, we leak that on driver unload.
I'll fix it.

cheers,
  Gerd
diff mbox series

Patch

diff --git a/drivers/gpu/drm/bochs/bochs.h b/drivers/gpu/drm/bochs/bochs.h
index e7a69077e4..06b8166efa 100644
--- a/drivers/gpu/drm/bochs/bochs.h
+++ b/drivers/gpu/drm/bochs/bochs.h
@@ -66,6 +66,7 @@  struct bochs_device {
 	u16 yres_virtual;
 	u32 stride;
 	u32 bpp;
+	struct edid *edid;
 
 	/* drm */
 	struct drm_device  *dev;
diff --git a/drivers/gpu/drm/bochs/bochs_hw.c b/drivers/gpu/drm/bochs/bochs_hw.c
index cacff73a64..6ce4cdac38 100644
--- a/drivers/gpu/drm/bochs/bochs_hw.c
+++ b/drivers/gpu/drm/bochs/bochs_hw.c
@@ -69,6 +69,41 @@  static void bochs_hw_set_little_endian(struct bochs_device *bochs)
 #define bochs_hw_set_native_endian(_b) bochs_hw_set_little_endian(_b)
 #endif
 
+static int bochs_load_edid(struct bochs_device *bochs)
+{
+	uint8_t *blob;
+	size_t i, len;
+	uint8_t num_exts;
+
+	if (!bochs->mmio)
+		return -1;
+
+	if ((readb(bochs->mmio+0) != 0x00 ||
+	     readb(bochs->mmio+1) != 0xff))
+		return -1;
+
+	num_exts = readb(bochs->mmio + 126);
+	len = EDID_LENGTH * (1 + num_exts);
+	if (len > 0x400 /* vga register offset */)
+		return -1;
+
+	kfree(bochs->edid);
+	bochs->edid = kmalloc(len, GFP_KERNEL);
+	blob = (void *)bochs->edid;
+	for (i = 0; i < len; i++) {
+		blob[i] = readb(bochs->mmio+i);
+	}
+
+	if (!drm_edid_is_valid(bochs->edid)) {
+		DRM_ERROR("EDID is not valid, ignoring.\n");
+		kfree(bochs->edid);
+		bochs->edid = NULL;
+		return -1;
+	}
+
+	return 0;
+}
+
 int bochs_hw_init(struct drm_device *dev)
 {
 	struct bochs_device *bochs = dev->dev_private;
@@ -150,6 +185,9 @@  int bochs_hw_init(struct drm_device *dev)
 	}
 
 noext:
+	if (bochs_load_edid(bochs) == 0)
+		DRM_INFO("Found EDID data blob.\n");
+
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/bochs/bochs_kms.c b/drivers/gpu/drm/bochs/bochs_kms.c
index 9bc5b438ae..b9931443a7 100644
--- a/drivers/gpu/drm/bochs/bochs_kms.c
+++ b/drivers/gpu/drm/bochs/bochs_kms.c
@@ -213,10 +213,17 @@  static void bochs_encoder_init(struct drm_device *dev)
 
 static int bochs_connector_get_modes(struct drm_connector *connector)
 {
-	int count;
+	struct bochs_device *bochs =
+		container_of(connector, struct bochs_device, connector);
+	int count = 0;
 
-	count = drm_add_modes_noedid(connector, 8192, 8192);
-	drm_set_preferred_mode(connector, defx, defy);
+	if (bochs->edid)
+		count = drm_add_edid_modes(connector, bochs->edid);
+
+	if (!count) {
+		count = drm_add_modes_noedid(connector, 8192, 8192);
+		drm_set_preferred_mode(connector, defx, defy);
+	}
 	return count;
 }
 
@@ -271,6 +278,11 @@  static void bochs_connector_init(struct drm_device *dev)
 	drm_connector_helper_add(connector,
 				 &bochs_connector_connector_helper_funcs);
 	drm_connector_register(connector);
+
+	if (bochs->edid) {
+		drm_connector_attach_edid_property(connector);
+		drm_connector_update_edid_property(connector, bochs->edid);
+	}
 }