Commit 2168fe3d authored by Ben Skeggs's avatar Ben Skeggs Committed by Greg Kroah-Hartman

drm/nouveau/disp/dp: ensure sink is powered up before attempting link training

commit 95664e66 upstream.

This can happen under some annoying circumstances, and is a quick fix
until more substantial changes can be made.

Fixed eDP mode changes on (at least) the Lenovo P50.
Signed-off-by: default avatarBen Skeggs <bskeggs@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a6976c7b
......@@ -328,6 +328,7 @@ nvkm_dp_train(struct work_struct *w)
.outp = outp,
}, *dp = &_dp;
u32 datarate = 0;
u8 pwr;
int ret;
if (!outp->base.info.location && disp->func->sor.magic)
......@@ -355,6 +356,15 @@ nvkm_dp_train(struct work_struct *w)
/* disable link interrupt handling during link training */
nvkm_notify_put(&outp->irq);
/* ensure sink is not in a low-power state */
if (!nvkm_rdaux(outp->aux, DPCD_SC00, &pwr, 1)) {
if ((pwr & DPCD_SC00_SET_POWER) != DPCD_SC00_SET_POWER_D0) {
pwr &= ~DPCD_SC00_SET_POWER;
pwr |= DPCD_SC00_SET_POWER_D0;
nvkm_wraux(outp->aux, DPCD_SC00, &pwr, 1);
}
}
/* enable down-spreading and execute pre-train script from vbios */
dp_link_train_init(dp, outp->dpcd[3] & 0x01);
......
......@@ -71,5 +71,11 @@
#define DPCD_LS0C_LANE1_POST_CURSOR2 0x0c
#define DPCD_LS0C_LANE0_POST_CURSOR2 0x03
/* DPCD Sink Control */
#define DPCD_SC00 0x00600
#define DPCD_SC00_SET_POWER 0x03
#define DPCD_SC00_SET_POWER_D0 0x01
#define DPCD_SC00_SET_POWER_D3 0x03
void nvkm_dp_train(struct work_struct *);
#endif
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