Re: [PATCH v3] drm/bochs: add edid support.

From: Jani Nikula
Date: Mon Oct 29 2018 - 13:44:34 EST


On Mon, 29 Oct 2018, Gerd Hoffmann <kraxel@xxxxxxxxxx> 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.

Any chance of making this use drm_get_edid() (requires an i2c_adapter)
or at least drm_do_get_edid()?

BR,
Jani.

>
> Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>
> ---
> drivers/gpu/drm/bochs/bochs.h | 1 +
> drivers/gpu/drm/bochs/bochs_hw.c | 39 +++++++++++++++++++++++++++++++++++++++
> drivers/gpu/drm/bochs/bochs_kms.c | 18 +++++++++++++++---
> 3 files changed, 55 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..db4afe94c5 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;
> }
>
> @@ -164,6 +202,7 @@ void bochs_hw_fini(struct drm_device *dev)
> if (bochs->fb_map)
> iounmap(bochs->fb_map);
> pci_release_regions(dev->pdev);
> + kfree(bochs->edid);
> }
>
> void bochs_hw_setmode(struct bochs_device *bochs,
> 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);
> + }
> }

--
Jani Nikula, Intel Open Source Graphics Center