Originally by Seth Forshee seth.forshee@canonical.com, 2012-10-04: Some dual graphics machines support muxing the DDC separately from the display, so make use of this functionality when reading the EDID on the inactive GPU. Also serialize drm_get_edid() with a mutex to avoid races on the DDC mux state.
Modified by Dave Airlie airlied@gmail.com, 2012-12-22: I can't figure out why I didn't like this, but I rewrote this [...] to lock/unlock the ddc lines [...]. I think I'd prefer something like that otherwise the interface got really ugly.
Modified by Lukas Wunner lukas@wunner.de, 2015-04 - 2015-09: v3: Move vga_switcheroo calls to a wrapper around drm_get_edid() which drivers can call on muxed machines. This avoids other drivers having to go through the vga_switcheroo motions even though they are never used on a muxed platform (Thierry Reding, Daniel Vetter, Alex Deucher)
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=88861 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=61115 Tested-by: Pierre Moreau pierre.morrow@free.fr [MBP 5,3 2009 nvidia MCP79 + G96 pre-retina 15"] Tested-by: William Brown william@blackhats.net.au [MBP 8,2 2011 intel SNB + amd turks pre-retina 15"] Tested-by: Lukas Wunner lukas@wunner.de [MBP 9,1 2012 intel IVB + nvidia GK107 pre-retina 15"] Cc: Seth Forshee seth.forshee@canonical.com Cc: Dave Airlie airlied@gmail.com Signed-off-by: Lukas Wunner lukas@wunner.de --- drivers/gpu/drm/drm_edid.c | 26 ++++++++++++++++++++++++++ include/drm/drm_crtc.h | 2 ++ 2 files changed, 28 insertions(+)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index c214f12..1e8f660 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -32,6 +32,7 @@ #include <linux/hdmi.h> #include <linux/i2c.h> #include <linux/module.h> +#include <linux/vga_switcheroo.h> #include <drm/drmP.h> #include <drm/drm_edid.h> #include <drm/drm_displayid.h> @@ -1389,6 +1390,31 @@ struct edid *drm_get_edid(struct drm_connector *connector, EXPORT_SYMBOL(drm_get_edid);
/** + * drm_get_edid_switcheroo - get EDID data for a vga_switcheroo output + * @connector: connector we're probing + * @adapter: I2C adapter to use for DDC + * + * Wrapper around drm_get_edid() for laptops with dual GPUs using one set of + * outputs. The wrapper adds the requisite vga_switcheroo calls to temporarily + * switch DDC to the GPU which is retrieving EDID. + * + * Return: Pointer to valid EDID or %NULL if we couldn't find any. + */ +struct edid *drm_get_edid_switcheroo(struct drm_connector *connector, + struct i2c_adapter *adapter) +{ + struct pci_dev *pdev = connector->dev->pdev; + struct edid *edid; + + vga_switcheroo_lock_ddc(pdev); + edid = drm_get_edid(connector, adapter); + vga_switcheroo_unlock_ddc(pdev); + + return edid; +} +EXPORT_SYMBOL(drm_get_edid_switcheroo); + +/** * drm_edid_duplicate - duplicate an EDID and the extensions * @edid: EDID to duplicate * diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index 3b040b3..65df8e7 100644 --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -2278,6 +2278,8 @@ extern void drm_property_destroy_user_blobs(struct drm_device *dev, extern bool drm_probe_ddc(struct i2c_adapter *adapter); extern struct edid *drm_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter); +extern struct edid *drm_get_edid_switcheroo(struct drm_connector *connector, + struct i2c_adapter *adapter); extern struct edid *drm_edid_duplicate(const struct edid *edid); extern int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid); extern void drm_mode_config_init(struct drm_device *dev);