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

From: Torsten Duwe
Date: Tue Feb 18 2020 - 10:47:50 EST


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@xxxxxxx>
---
https://patchwork.freedesktop.org/patch/343004/
https://lists.freedesktop.org/archives/dri-devel/2020-January/253535.html

--- 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;