drm/nouveau/agp: add a quirk list to limit agp modes

Certain combinations of hardware can't actually support the maximum
detected speed. Add a quirk list that lists pairs of hostbridge/chip pci
ids and the mode that they should work with.

See https://bugs.freedesktop.org/show_bug.cgi?id=20341

Reported-by: Jason Detring <detringj@gmail.com>
Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 39 insertions, 5 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_agp.c b/drivers/gpu/drm/nouveau/nouveau_agp.c
index 6e7a55f93a85..2953c4e91e1a 100644
--- a/drivers/gpu/drm/nouveau/nouveau_agp.c
+++ b/drivers/gpu/drm/nouveau/nouveau_agp.c
@@ -11,10 +11,28 @@ MODULE_PARM_DESC(agpmode, "AGP mode (0 to disable AGP)");
 static int nouveau_agpmode = -1;
 module_param_named(agpmode, nouveau_agpmode, int, 0400);
 
+struct nouveau_agpmode_quirk {
+        u16 hostbridge_vendor;
+        u16 hostbridge_device;
+        u16 chip_vendor;
+        u16 chip_device;
+        int mode;
+};
+
+static struct nouveau_agpmode_quirk nouveau_agpmode_quirk_list[] = {
+        /* VIA Apollo PRO133x / GeForce FX 5600 Ultra, max agpmode 2, fdo #20341 */
+        { PCI_VENDOR_ID_VIA, 0x0691, PCI_VENDOR_ID_NVIDIA, 0x0311, 2 },
+
+        {},
+};
+
 static unsigned long
-get_agp_mode(struct nouveau_drm *drm, unsigned long mode)
+get_agp_mode(struct nouveau_drm *drm, const struct drm_agp_info *info)
 {
         struct nouveau_device *device = nv_device(drm->device);
+        struct nouveau_agpmode_quirk *quirk = nouveau_agpmode_quirk_list;
+        int agpmode = nouveau_agpmode;
+        unsigned long mode = info->mode;
 
         /*
          * FW seems to be broken on nv18, it makes the card lock up
@@ -24,11 +42,27 @@ get_agp_mode(struct nouveau_drm *drm, unsigned long mode)
                 mode &= ~PCI_AGP_COMMAND_FW;
 
         /*
+         * Go through the quirks list and adjust the agpmode accordingly.
+         */
+        while (agpmode == -1 && quirk->hostbridge_vendor) {
+                if (info->id_vendor == quirk->hostbridge_vendor &&
+                    info->id_device == quirk->hostbridge_device &&
+                    device->pdev->vendor == quirk->chip_vendor &&
+                    device->pdev->device == quirk->chip_device) {
+                        agpmode = quirk->mode;
+                        nv_info(device, "Forcing agp mode to %dX. Use agpmode to override.\n",
+                                agpmode);
+                        break;
+                }
+                ++quirk;
+        }
+
+        /*
          * AGP mode set in the command line.
          */
-        if (nouveau_agpmode > 0) {
+        if (agpmode > 0) {
                 bool agpv3 = mode & 0x8;
-                int rate = agpv3 ? nouveau_agpmode / 4 : nouveau_agpmode;
+                int rate = agpv3 ? agpmode / 4 : agpmode;
 
                 mode = (mode & ~0x7) | (rate & 0x7);
         }
@@ -90,7 +124,7 @@ nouveau_agp_reset(struct nouveau_drm *drm)
                 if (ret)
                         return;
 
-                mode.mode  = get_agp_mode(drm, info.mode);
+                mode.mode  = get_agp_mode(drm, &info);
                 mode.mode &= ~PCI_AGP_COMMAND_FW;
 
                 ret = drm_agp_enable(dev, mode);
@@ -139,7 +173,7 @@ nouveau_agp_init(struct nouveau_drm *drm)
         }
 
         /* see agp.h for the AGPSTAT_* modes available */
-        mode.mode = get_agp_mode(drm, info.mode);
+        mode.mode = get_agp_mode(drm, &info);
 
         ret = drm_agp_enable(dev, mode);
         if (ret) {