drm/nouveau/disp/dp: maintain link in response to hpd signal
This previously worked for the most part due to userspace doing a
modeset in response to HPD interrupts. This will allow us to
properly handle cases where sync is lost for other reasons, or if
userspace isn't caring.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/core/engine/disp/dport.c b/drivers/gpu/drm/nouveau/core/engine/disp/dport.c
index 5d4b034..c2bf611 100644
--- a/drivers/gpu/drm/nouveau/core/engine/disp/dport.c
+++ b/drivers/gpu/drm/nouveau/core/engine/disp/dport.c
@@ -102,7 +102,7 @@
if (outp->dpcd[DPCD_RC02] & DPCD_RC02_ENHANCED_FRAME_CAP)
sink[1] |= DPCD_LC01_ENHANCED_FRAME_EN;
- return nv_wraux(outp->base.edid, DPCD_LC00, sink, 2);
+ return nv_wraux(outp->base.edid, DPCD_LC00_LINK_BW_SET, sink, 2);
}
static void
@@ -313,14 +313,16 @@
{}
};
-int
-nouveau_dp_train(struct nvkm_output_dp *outp, u32 datarate)
+void
+nouveau_dp_train(struct work_struct *w)
{
+ struct nvkm_output_dp *outp = container_of(w, typeof(*outp), lt.work);
struct nouveau_disp *disp = nouveau_disp(outp);
const struct dp_rates *cfg = nouveau_dp_rates;
struct dp_state _dp = {
.outp = outp,
}, *dp = &_dp;
+ u32 datarate = 0;
int ret;
/* bring capabilities within encoder limits */
@@ -342,6 +344,9 @@
}
cfg--;
+ /* disable link interrupt handling during link training */
+ nouveau_event_put(outp->irq);
+
/* enable down-spreading and execute pre-train script from vbios */
dp_link_train_init(dp, outp->dpcd[3] & 0x01);
@@ -370,12 +375,16 @@
}
}
- /* finish link training */
+ /* finish link training and execute post-train script from vbios */
dp_set_training_pattern(dp, 0);
if (ret < 0)
ERR("link training failed\n");
- /* execute post-train script from vbios */
dp_link_train_fini(dp);
- return (ret < 0) ? false : true;
+
+ /* signal completion and enable link interrupt handling */
+ DBG("training complete\n");
+ atomic_set(&outp->lt.done, 1);
+ wake_up(&outp->lt.wait);
+ nouveau_event_get(outp->irq);
}
diff --git a/drivers/gpu/drm/nouveau/core/engine/disp/dport.h b/drivers/gpu/drm/nouveau/core/engine/disp/dport.h
index 2712e31..5628d2d5 100644
--- a/drivers/gpu/drm/nouveau/core/engine/disp/dport.h
+++ b/drivers/gpu/drm/nouveau/core/engine/disp/dport.h
@@ -13,8 +13,7 @@
#define DPCD_RC0E_AUX_RD_INTERVAL 0x0000e
/* DPCD Link Configuration */
-#define DPCD_LC00 0x00100
-#define DPCD_LC00_LINK_BW_SET 0xff
+#define DPCD_LC00_LINK_BW_SET 0x00100
#define DPCD_LC01 0x00101
#define DPCD_LC01_ENHANCED_FRAME_EN 0x80
#define DPCD_LC01_LANE_COUNT_SET 0x1f
@@ -71,4 +70,6 @@
#define DPCD_LS0C_LANE1_POST_CURSOR2 0x0c
#define DPCD_LS0C_LANE0_POST_CURSOR2 0x03
+void nouveau_dp_train(struct work_struct *);
+
#endif
diff --git a/drivers/gpu/drm/nouveau/core/engine/disp/nv50.c b/drivers/gpu/drm/nouveau/core/engine/disp/nv50.c
index a73bc15..90974cd 100644
--- a/drivers/gpu/drm/nouveau/core/engine/disp/nv50.c
+++ b/drivers/gpu/drm/nouveau/core/engine/disp/nv50.c
@@ -1457,6 +1457,24 @@
if (!outp)
return;
+ /* we allow both encoder attach and detach operations to occur
+ * within a single supervisor (ie. modeset) sequence. the
+ * encoder detach scripts quite often switch off power to the
+ * lanes, which requires the link to be re-trained.
+ *
+ * this is not generally an issue as the sink "must" (heh)
+ * signal an irq when it's lost sync so the driver can
+ * re-train.
+ *
+ * however, on some boards, if one does not configure at least
+ * the gpu side of the link *before* attaching, then various
+ * things can go horribly wrong (PDISP disappearing from mmio,
+ * third supervisor never happens, etc).
+ *
+ * the solution is simply to retrain here, if necessary. last
+ * i checked, the binary driver userspace does not appear to
+ * trigger this situation (it forces an UPDATE between steps).
+ */
if (outp->info.type == DCB_OUTPUT_DP) {
u32 soff = (ffs(outp->info.or) - 1) * 0x08;
u32 ctrl, datarate;
@@ -1478,7 +1496,8 @@
break;
}
- nouveau_dp_train((void *)outp, datarate / soff);
+ if (nvkm_output_dp_train(outp, datarate / soff, true))
+ ERR("link not trained before attach\n");
}
exec_clkcmp(priv, head, 0, pclk, &conf);
diff --git a/drivers/gpu/drm/nouveau/core/engine/disp/nvd0.c b/drivers/gpu/drm/nouveau/core/engine/disp/nvd0.c
index 77e7ade..4eb16e9 100644
--- a/drivers/gpu/drm/nouveau/core/engine/disp/nvd0.c
+++ b/drivers/gpu/drm/nouveau/core/engine/disp/nvd0.c
@@ -1138,6 +1138,7 @@
if (!outp)
return;
+ /* see note in nv50_disp_intr_unk20_2() */
if (outp->info.type == DCB_OUTPUT_DP) {
u32 sync = nv_rd32(priv, 0x660404 + (head * 0x300));
switch ((sync & 0x000003c0) >> 6) {
@@ -1149,7 +1150,8 @@
break;
}
- nouveau_dp_train((void *)outp, pclk);
+ if (nvkm_output_dp_train(outp, pclk, true))
+ ERR("link not trained before attach\n");
}
exec_clkcmp(priv, head, 0, pclk, &conf);
diff --git a/drivers/gpu/drm/nouveau/core/engine/disp/outpdp.c b/drivers/gpu/drm/nouveau/core/engine/disp/outpdp.c
index 7f55887..52c299c 100644
--- a/drivers/gpu/drm/nouveau/core/engine/disp/outpdp.c
+++ b/drivers/gpu/drm/nouveau/core/engine/disp/outpdp.c
@@ -28,6 +28,75 @@
#include "conn.h"
#include "dport.h"
+int
+nvkm_output_dp_train(struct nvkm_output *base, u32 datarate, bool wait)
+{
+ struct nvkm_output_dp *outp = (void *)base;
+ bool retrain = true;
+ u8 link[2], stat[3];
+ u32 rate;
+ int ret, i;
+
+ /* check that the link is trained at a high enough rate */
+ ret = nv_rdaux(outp->base.edid, DPCD_LC00_LINK_BW_SET, link, 2);
+ if (ret) {
+ DBG("failed to read link config, assuming no sink\n");
+ goto done;
+ }
+
+ rate = link[0] * 27000 * (link[1] & DPCD_LC01_LANE_COUNT_SET);
+ if (rate < ((datarate / 8) * 10)) {
+ DBG("link not trained at sufficient rate\n");
+ goto done;
+ }
+
+ /* check that link is still trained */
+ ret = nv_rdaux(outp->base.edid, DPCD_LS02, stat, 3);
+ if (ret) {
+ DBG("failed to read link status, assuming no sink\n");
+ goto done;
+ }
+
+ if (stat[2] & DPCD_LS04_INTERLANE_ALIGN_DONE) {
+ for (i = 0; i < (link[1] & DPCD_LC01_LANE_COUNT_SET); i++) {
+ u8 lane = (stat[i >> 1] >> ((i & 1) * 4)) & 0x0f;
+ if (!(lane & DPCD_LS02_LANE0_CR_DONE) ||
+ !(lane & DPCD_LS02_LANE0_CHANNEL_EQ_DONE) ||
+ !(lane & DPCD_LS02_LANE0_SYMBOL_LOCKED)) {
+ DBG("lane %d not equalised\n", lane);
+ goto done;
+ }
+ }
+ retrain = false;
+ } else {
+ DBG("no inter-lane alignment\n");
+ }
+
+done:
+ if (retrain || !atomic_read(&outp->lt.done)) {
+ /* no sink, but still need to configure source */
+ if (outp->dpcd[DPCD_RC00_DPCD_REV] == 0x00) {
+ outp->dpcd[DPCD_RC01_MAX_LINK_RATE] =
+ outp->base.info.dpconf.link_bw;
+ outp->dpcd[DPCD_RC02] =
+ outp->base.info.dpconf.link_nr;
+ }
+ atomic_set(&outp->lt.done, 0);
+ schedule_work(&outp->lt.work);
+ } else {
+ nouveau_event_get(outp->irq);
+ }
+
+ if (wait) {
+ if (!wait_event_timeout(outp->lt.wait,
+ atomic_read(&outp->lt.done),
+ msecs_to_jiffies(2000)))
+ ret = -ETIMEDOUT;
+ }
+
+ return ret;
+}
+
static void
nvkm_output_dp_enable(struct nvkm_output_dp *outp, bool present)
{
@@ -38,12 +107,14 @@
DBG("aux power -> always\n");
outp->present = true;
}
+ nvkm_output_dp_train(&outp->base, 0, true);
} else {
if (outp->present) {
nouveau_i2c(port)->release_pad(port);
DBG("aux power -> demand\n");
outp->present = false;
}
+ atomic_set(&outp->lt.done, 0);
}
}
@@ -78,7 +149,7 @@
}
if (type & NVKM_I2C_IRQ) {
- nouveau_event_get(outp->irq);
+ nvkm_output_dp_train(&outp->base, 0, true);
send |= NVKM_HPD_IRQ;
}
@@ -159,6 +230,11 @@
DBG("bios dp %02x %02x %02x %02x\n", outp->version, hdr, cnt, len);
+ /* link training */
+ INIT_WORK(&outp->lt.work, nouveau_dp_train);
+ init_waitqueue_head(&outp->lt.wait);
+ atomic_set(&outp->lt.done, 0);
+
/* link maintenance */
ret = nouveau_event_new(i2c->ntfy, NVKM_I2C_IRQ, outp->base.edid->index,
nvkm_output_dp_service, outp, &outp->irq);
diff --git a/drivers/gpu/drm/nouveau/core/engine/disp/outpdp.h b/drivers/gpu/drm/nouveau/core/engine/disp/outpdp.h
index 4c32cf5..ff33ba1 100644
--- a/drivers/gpu/drm/nouveau/core/engine/disp/outpdp.h
+++ b/drivers/gpu/drm/nouveau/core/engine/disp/outpdp.h
@@ -18,6 +18,12 @@
atomic_t pending;
bool present;
u8 dpcd[16];
+
+ struct {
+ struct work_struct work;
+ wait_queue_head_t wait;
+ atomic_t done;
+ } lt;
};
#define nvkm_output_dp_create(p,e,c,b,i,d) \
@@ -54,6 +60,6 @@
int (*drv_ctl)(struct nvkm_output_dp *, int ln, int vs, int pe, int pc);
};
-int nouveau_dp_train(struct nvkm_output_dp *, u32 rate);
+int nvkm_output_dp_train(struct nvkm_output *, u32 rate, bool wait);
#endif