[RESEND2][PATCH] drm/bridge: analogix-anx6345: Fix drm_dp_link helper removal

[Torsten Duwe]

drm_dp_link_rate_to_bw_code and ...bw_code_to_link_rate simply divide by
and multiply with 27000, respectively. Avoid an overflow in the u8 dpcd[0]
and the multiply+divide alltogether.

fixes: e1cff82c1097bda2478 ("fix anx6345 compilation for v5.5")
Signed-off-by: Torsten Duwe <duwe at suse.de>
---
https://patchwork.freedesktop.org/patch/343004/
https://lists.freedesktop.org/archives/dri-devel/2020-January/253535.html

Can someone please review this? It's equivalent to commit
3e138a63d6674a4567a018a31 which just made it into drm-tip.

--- a/drivers/gpu/drm/bridge/analogix/analogix-anx6345.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix-anx6345.c
@@ -210,10 +210,9 @@ static int anx6345_dp_link_training(struct anx6345 *anx6345)
 	if (err)
 		return err;
 
-	dpcd[0] = drm_dp_max_link_rate(anx6345->dpcd);
-	dpcd[0] = drm_dp_link_rate_to_bw_code(dpcd[0]);
 	err = regmap_write(anx6345->map[I2C_IDX_DPTX],
-			   SP_DP_MAIN_LINK_BW_SET_REG, dpcd[0]);
+			   SP_DP_MAIN_LINK_BW_SET_REG,
+			   anx6345->dpcd[DP_MAX_LINK_RATE]);
 	if (err)
 		return err;