Return-Path: Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Mauro Carvalho Chehab" , "Sakari Ailus" , "Colin Ian King" Date: Sun, 11 Nov 2018 19:49:05 +0000 Message-ID: Subject: [PATCH 3.16 059/366] media: smiapp: fix timeout checking in smiapp_read_nvm In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.16.61-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Colin Ian King commit 7a2148dfda8001c983f0effd9afd8a7fa58e99c4 upstream. The current code decrements the timeout counter i and the end of each loop i is incremented, so the check for timeout will always be false and hence the timeout mechanism is just a dead code path. Potentially, if the RD_READY bit is not set, we could end up in an infinite loop. Fix this so the timeout starts from 1000 and decrements to zero, if at the end of the loop i is zero we have a timeout condition. Detected by CoverityScan, CID#1324008 ("Logically dead code") Fixes: ccfc97bdb5ae ("[media] smiapp: Add driver") Signed-off-by: Colin Ian King Signed-off-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Ben Hutchings --- drivers/media/i2c/smiapp/smiapp-core.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) --- a/drivers/media/i2c/smiapp/smiapp-core.c +++ b/drivers/media/i2c/smiapp/smiapp-core.c @@ -899,7 +899,7 @@ static int smiapp_read_nvm(struct smiapp if (rval) goto out; - for (i = 0; i < 1000; i++) { + for (i = 1000; i > 0; i--) { rval = smiapp_read( sensor, SMIAPP_REG_U8_DATA_TRANSFER_IF_1_STATUS, &s); @@ -910,11 +910,10 @@ static int smiapp_read_nvm(struct smiapp if (s & SMIAPP_DATA_TRANSFER_IF_1_STATUS_RD_READY) break; - if (--i == 0) { - rval = -ETIMEDOUT; - goto out; - } - + } + if (!i) { + rval = -ETIMEDOUT; + goto out; } for (i = 0; i < SMIAPP_NVM_PAGE_SIZE; i++) {