This addresses <http://bugzilla.kernel.org/show_bug.cgi?id=15021>. DRM drivers may fail to probe their devices when the associated AGP GART does not yet have a driver, so we reprobe unbound VGA devices when a GART device is added. Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- This is intended to address the dependency problem highlighted in the above bug report. That specific bug can be fixed by adding a module dependency from i915 to intel_agp, but in general there is no fixed relationship betweem DRM and GART drivers. There is a narrow race between the check for a current driver binding and the call to device_reprobe(). This could be closed by adding a variant on device_attach() and device_reprobe() that is a no-op for bound devices. Ben. drivers/char/agp/backend.c | 20 ++++++++++++++++++++ 1 files changed, 20 insertions(+), 0 deletions(-) diff --git a/drivers/char/agp/backend.c b/drivers/char/agp/backend.c index c3ab46d..f9680bf 100644 --- a/drivers/char/agp/backend.c +++ b/drivers/char/agp/backend.c @@ -36,6 +36,7 @@ #include <linux/agp_backend.h> #include <linux/agpgart.h> #include <linux/vmalloc.h> +#include <linux/workqueue.h> #include <asm/io.h> #include "agp.h" @@ -281,6 +282,24 @@ void agp_put_bridge(struct agp_bridge_data *bridge) EXPORT_SYMBOL(agp_put_bridge); +/* + * DRM drivers may fail to probe their devices when the associated AGP + * GART does not yet have a driver, so we reprobe unbound VGA devices + * when a GART device is added. This problem applies not only to true + * AGP devices which would be children of the affected bridge, but + * also to PCI Express devices that may be siblings of the GART + * device. Therefore iterate over all PCI VGA devices. + */ +static void agp_probe_video(struct work_struct *work) +{ + struct pci_dev *pdev = NULL; + + while ((pdev = pci_get_class(0x030000, pdev)) != NULL) { + if (!pdev->dev.driver && device_reprobe(&pdev->dev)) + pr_err(PFX "failed to reprobe %s\n", pci_name(pdev)); +} +static DECLARE_WORK(agp_probe_video_work, agp_probe_video); + int agp_add_bridge(struct agp_bridge_data *bridge) { int error; @@ -324,6 +343,7 @@ int agp_add_bridge(struct agp_bridge_data *bridge) } list_add(&bridge->list, &agp_bridges); + schedule_work(&agp_probe_video_work); return 0; frontend_err: -- 1.6.6.2 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
