From 2a81e844d1ffabdf4f9902b83dca35ea86895eab Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Mon, 4 Dec 2023 15:29:00 +0300 Subject: [PATCH] drm/bridge: nxp-ptn3460: fix i2c_master_send() error checking commit 914437992876838662c968cb416f832110fb1093 upstream. The i2c_master_send/recv() functions return negative error codes or the number of bytes that were able to be sent/received. This code has two problems. 1) Instead of checking if all the bytes were sent or received, it checks that at least one byte was sent or received. 2) If there was a partial send/receive then we should return a negative error code but this code returns success. Fixes: a9fe713d7d45 ("drm/bridge: Add PTN3460 bridge driver") Cc: stable@vger.kernel.org Signed-off-by: Dan Carpenter Reviewed-by: Robert Foss Signed-off-by: Robert Foss Link: https://patchwork.freedesktop.org/patch/msgid/0cdc2dce-ca89-451a-9774-1482ab2f4762@moroto.mountain Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/bridge/nxp-ptn3460.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/bridge/nxp-ptn3460.c b/drivers/gpu/drm/bridge/nxp-ptn3460.c index 0851101a8c72..db5ec89366a2 100644 --- a/drivers/gpu/drm/bridge/nxp-ptn3460.c +++ b/drivers/gpu/drm/bridge/nxp-ptn3460.c @@ -56,13 +56,13 @@ static int ptn3460_read_bytes(struct ptn3460_bridge *ptn_bridge, char addr, ret = i2c_master_send(ptn_bridge->client, &addr, 1); if (ret <= 0) { DRM_ERROR("Failed to send i2c command, ret=%d\n", ret); - return ret; + return ret ?: -EIO; } ret = i2c_master_recv(ptn_bridge->client, buf, len); - if (ret <= 0) { + if (ret != len) { DRM_ERROR("Failed to recv i2c data, ret=%d\n", ret); - return ret; + return ret < 0 ? ret : -EIO; } return 0; @@ -78,9 +78,9 @@ static int ptn3460_write_byte(struct ptn3460_bridge *ptn_bridge, char addr, buf[1] = val; ret = i2c_master_send(ptn_bridge->client, buf, ARRAY_SIZE(buf)); - if (ret <= 0) { + if (ret != ARRAY_SIZE(buf)) { DRM_ERROR("Failed to send i2c command, ret=%d\n", ret); - return ret; + return ret < 0 ? ret : -EIO; } return 0;