Merge branch 'linux-5.3' of git://github.com/skeggsb/linux into drm-fixes

Fixes i2c on DP with some docks.

Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Ben Skeggs <skeggsb@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/CACAvsv713t2_BQ44gVV7Lqic6Vwmhq0r4FB5v-t0kD1jzFrbmQ@mail.gmail.com

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/aux.c b/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/aux.c
index b4e7404fe660e24937bde1e518533feecad376d9..a11637b0f6ccf43cc39c417dc64a8fb349815a22 100644 (file)
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/aux.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/aux.c
@@ -40,8 +40,7 @@ nvkm_i2c_aux_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
                u8 *ptr = msg->buf;
 
                while (remaining) {
-                       u8 cnt = (remaining > 16) ? 16 : remaining;
-                       u8 cmd;
+                       u8 cnt, retries, cmd;
 
                        if (msg->flags & I2C_M_RD)
                                cmd = 1;
@@ -51,10 +50,19 @@ nvkm_i2c_aux_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
                        if (mcnt || remaining > 16)
                                cmd |= 4; /* MOT */
 
-                       ret = aux->func->xfer(aux, true, cmd, msg->addr, ptr, &cnt);
-                       if (ret < 0) {
-                               nvkm_i2c_aux_release(aux);
-                               return ret;
+                       for (retries = 0, cnt = 0;
+                            retries < 32 && !cnt;
+                            retries++) {
+                               cnt = min_t(u8, remaining, 16);
+                               ret = aux->func->xfer(aux, true, cmd,
+                                                     msg->addr, ptr, &cnt);
+                               if (ret < 0)
+                                       goto out;
+                       }
+                       if (!cnt) {
+                               AUX_TRACE(aux, "no data after 32 retries");
+                               ret = -EIO;
+                               goto out;
                        }
 
                        ptr += cnt;
@@ -64,8 +72,10 @@ nvkm_i2c_aux_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
                msg++;
        }
 
+       ret = num;
+out:
        nvkm_i2c_aux_release(aux);
-       return num;
+       return ret;
 }
 
 static u32