From: Ben Skeggs bskeggs@redhat.com
stable inclusion from linux-4.19.206 commit d386a4b54607cf6f76e23815c2c9a3abc1d66882
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[ 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 Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c | 2 +- drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.h | 1 + drivers/gpu/drm/nouveau/nvkm/engine/disp/outp.c | 9 +++++++++ 3 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c index 818d21bd28d31..1d2837c5a8f29 100644 --- 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 495f665a0ee68..12d6ff4cfa95d 100644 --- 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 c62030c96fba0..4b1c72fd8f039 100644 --- 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; }