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.
Signed-off-by: Seth Forshee seth.forshee@canonical.com --- drivers/gpu/drm/drm_edid.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index b7ee230..b389269 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -31,6 +31,7 @@ #include <linux/slab.h> #include <linux/i2c.h> #include <linux/module.h> +#include <linux/vga_switcheroo.h> #include "drmP.h" #include "drm_edid.h" #include "drm_edid_modes.h" @@ -82,6 +83,8 @@ struct detailed_mode_closure { #define LEVEL_GTF2 2 #define LEVEL_CVT 3
+static DEFINE_MUTEX(drm_edid_mutex); + static struct edid_quirk { char vendor[4]; int product_id; @@ -398,12 +401,26 @@ struct edid *drm_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter) { struct edid *edid = NULL; + struct pci_dev *pdev = connector->dev->pdev; + struct pci_dev *active_pdev = NULL; + + mutex_lock(&drm_edid_mutex); + + if (pdev) { + active_pdev = vga_switcheroo_get_active_client(); + if (active_pdev != pdev) + vga_switcheroo_switch_ddc(pdev); + }
if (drm_probe_ddc(adapter)) edid = (struct edid *)drm_do_get_edid(connector, adapter);
+ if (active_pdev && active_pdev != pdev) + vga_switcheroo_switch_ddc(active_pdev); + connector->display_info.raw_edid = (char *)edid;
+ mutex_unlock(&drm_edid_mutex); return edid;
}