drm/nouveau/disp: power down unused DP links during init

[ Upstream commit 6eaa1f3c59a707332e921e32782ffcad49915c5e ]

When booted with multiple displays attached, the EFI GOP driver on (at
least) Ampere, can leave DP links powered up that aren't being used to
display anything.  This confuses our tracking of SOR routing, with the
likely result being a failed modeset and display engine hang.

Fix this by (ab?)using the DisableLT IED script to power-down the link,
restoring HW to a state the driver expects.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c
index 818d21bd28d3122898f11d88c87bc0fec348c5ee..1d2837c5a8f29da78fc963b3b3cd45a2c2d09fa6 100644 (file)
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c
@@ -419,7 +419,7 @@ nvkm_dp_train(struct nvkm_dp *dp, u32 dataKBps)
        return ret;
 }
 
-static void
+void
 nvkm_dp_disable(struct nvkm_outp *outp, struct nvkm_ior *ior)
 {
        struct nvkm_dp *dp = nvkm_dp(outp);

diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.h b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.h
index 495f665a0ee683308fc1211b4b2e66a12efe39cf..12d6ff4cfa95d7c4b8fcdef002a2643ed4ffd354 100644 (file)
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.h
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.h
@@ -32,6 +32,7 @@ struct nvkm_dp {
 
 int nvkm_dp_new(struct nvkm_disp *, int index, struct dcb_output *,
                struct nvkm_outp **);
+void nvkm_dp_disable(struct nvkm_outp *, struct nvkm_ior *);
 
 /* DPCD Receiver Capabilities */
 #define DPCD_RC00_DPCD_REV                                              0x00000

diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/outp.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/outp.c
index c62030c96fba0932decd996fd46f3f9a308864d9..4b1c72fd8f039c5cf2e9365bcfc46fa1bb961420 100644 (file)
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/outp.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/outp.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs
  */
 #include "outp.h"
+#include "dp.h"
 #include "ior.h"
 
 #include <subdev/bios.h>
@@ -216,6 +217,14 @@ nvkm_outp_init_route(struct nvkm_outp *outp)
        if (!ior->arm.head || ior->arm.proto != proto) {
                OUTP_DBG(outp, "no heads (%x %d %d)", ior->arm.head,
                         ior->arm.proto, proto);
+
+               /* The EFI GOP driver on Ampere can leave unused DP links routed,
+                * which we don't expect.  The DisableLT IED script *should* get
+                * us back to where we need to be.
+                */
+               if (ior->func->route.get && !ior->arm.head && outp->info.type == DCB_OUTPUT_DP)
+                       nvkm_dp_disable(outp, ior);
+
                return;
        }