Re: [PATCH] drm/bridge: parade-ps8640: check return values in ps8640_aux_transfer()
From: Tim Gardner
Date: Fri Sep 24 2021 - 12:03:34 EST
On 9/24/21 9:26 AM, Tim Gardner wrote:
Coverity complains of an unused return code:
CID 120459 (#1 of 1): Unchecked return value (CHECKED_RETURN)
7. check_return: Calling regmap_bulk_write without checking return value (as is
done elsewhere 199 out of 291 times).
204 regmap_bulk_write(map, PAGE0_SWAUX_ADDR_7_0, addr_len,
205 ARRAY_SIZE(addr_len));
While I was at it I noticed 2 other places where return codes were not being
used, or used incorrectly (which is a real bug).
Fix these errors by correctly using the returned error codes.
Cc: William Breathitt Gray <vilhelm.gray@xxxxxxxxx>
Cc: Syed Nayyar Waris <syednwaris@xxxxxxxxx>
Cc: Andrzej Hajda <a.hajda@xxxxxxxxxxx>
Cc: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
Cc: Robert Foss <robert.foss@xxxxxxxxxx>
Cc: Laurent Pinchart <Laurent.pinchart@xxxxxxxxxxxxxxxx>
Cc: Jonas Karlman <jonas@xxxxxxxxx>
Cc: Jernej Skrabec <jernej.skrabec@xxxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxx>
Cc: Daniel Vetter <daniel@xxxxxxxx>
Cc: linux-iio@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Tim Gardner <tim.gardner@xxxxxxxxxxxxx>
---
drivers/gpu/drm/bridge/parade-ps8640.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c b/drivers/gpu/drm/bridge/parade-ps8640.c
index 3aaa90913bf8..591da962970a 100644
--- a/drivers/gpu/drm/bridge/parade-ps8640.c
+++ b/drivers/gpu/drm/bridge/parade-ps8640.c
@@ -201,8 +201,12 @@ static ssize_t ps8640_aux_transfer(struct drm_dp_aux *aux,
addr_len[PAGE0_SWAUX_LENGTH - base] = (len == 0) ? SWAUX_NO_PAYLOAD :
((len - 1) & SWAUX_LENGTH_MASK);
- regmap_bulk_write(map, PAGE0_SWAUX_ADDR_7_0, addr_len,
+ ret = regmap_bulk_write(map, PAGE0_SWAUX_ADDR_7_0, addr_len,
ARRAY_SIZE(addr_len));
+ if (ret) {
+ DRM_DEV_ERROR(dev, "failed to bulk write ADDR_7_0: %d\n", ret);
+ return ret;
+ }
if (len && (request == DP_AUX_NATIVE_WRITE ||
request == DP_AUX_I2C_WRITE)) {
@@ -218,13 +222,17 @@ static ssize_t ps8640_aux_transfer(struct drm_dp_aux *aux,
}
}
- regmap_write(map, PAGE0_SWAUX_CTRL, SWAUX_SEND);
+ ret = regmap_write(map, PAGE0_SWAUX_CTRL, SWAUX_SEND);
+ if (ret) {
+ DRM_DEV_ERROR(dev, "failed to write SEND: %d\n", ret);
+ return ret;
+ }
/* Zero delay loop because i2c transactions are slow already */
regmap_read_poll_timeout(map, PAGE0_SWAUX_CTRL, data,
!(data & SWAUX_SEND), 0, 50 * 1000);
- regmap_read(map, PAGE0_SWAUX_STATUS, &data);
+ ret = regmap_read(map, PAGE0_SWAUX_STATUS, &data);
if (ret) {
DRM_DEV_ERROR(dev, "failed to read PAGE0_SWAUX_STATUS: %d\n",
ret);
I forgot to mention this patch is for linux-next next-20210924.
-----------
Tim Gardner
Canonical, Inc