drm/nouveau/disp/dp: make use of postcursor when its available
And at the same time, obey the spec better wrt out-of-range requests.
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 c2bf611..39562d4 100644
--- a/drivers/gpu/drm/nouveau/core/engine/disp/dport.c
+++ b/drivers/gpu/drm/nouveau/core/engine/disp/dport.c
@@ -130,18 +130,28 @@
for (i = 0; i < dp->link_nr; i++) {
u8 lane = (dp->stat[4 + (i >> 1)] >> ((i & 1) * 4)) & 0xf;
+ u8 lpc2 = (dp->pc2stat >> (i * 2)) & 0x3;
u8 lpre = (lane & 0x0c) >> 2;
u8 lvsw = (lane & 0x03) >> 0;
+ u8 hivs = 3 - lpre;
+ u8 hipe = 3;
+ u8 hipc = 3;
+
+ if (lpc2 >= hipc)
+ lpc2 = hipc | DPCD_LC0F_LANE0_MAX_POST_CURSOR2_REACHED;
+ if (lpre >= hipe) {
+ lpre = hipe | DPCD_LC03_MAX_SWING_REACHED; /* yes. */
+ lvsw = hivs = 3 - (lpre & 3);
+ } else
+ if (lvsw >= hivs) {
+ lvsw = hivs | DPCD_LC03_MAX_SWING_REACHED;
+ }
dp->conf[i] = (lpre << 3) | lvsw;
- if (lvsw == 3)
- dp->conf[i] |= DPCD_LC03_MAX_SWING_REACHED;
- if (lpre == 3)
- dp->conf[i] |= DPCD_LC03_MAX_PRE_EMPHASIS_REACHED;
- dp->pc2conf[i >> 1] |= 4 << ((i & 1) * 4);
+ dp->pc2conf[i >> 1] |= lpc2 << ((i & 1) * 4);
- DBG("config lane %d %02x\n", i, dp->conf[i]);
- impl->drv_ctl(outp, i, lvsw, lpre, 0);
+ DBG("config lane %d %02x %02x\n", i, dp->conf[i], lpc2);
+ impl->drv_ctl(outp, i, lvsw & 3, lpre & 3, lpc2 & 3);
}
ret = nv_wraux(outp->base.edid, DPCD_LC03(0), dp->conf, 4);