From mboxrd@z Thu Jan 1 00:00:00 1970 From: Himanshu Madhani Date: Thu, 17 Dec 2015 01:25:16 +0000 Subject: Re: [patch] qla2xxx: fix a timeout loop Message-Id: List-Id: References: <20151216110746.GB21018@mwanda> In-Reply-To: <20151216110746.GB21018@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: Dan Carpenter , Dept-Eng QLA2xxx Upstream Cc: "James E.J. Bottomley" , "Martin K. Petersen" , linux-scsi , "kernel-janitors@vger.kernel.org" Hi Dan,=20 On 12/16/15, 3:07 AM, "linux-scsi-owner@vger.kernel.org on behalf of Dan Carpenter" wrote: >After the loop we test for "if (!retries) " as a failure, but actually >the post-op here will end with retries set to -1. I have fixed this by >using a pre-op instead. > >Fixes: 7ec0effd30bb ('[SCSI] qla2xxx: Add support for ISP8044.') >Signed-off-by: Dan Carpenter > >diff --git a/drivers/scsi/qla2xxx/qla_nx2.c >b/drivers/scsi/qla2xxx/qla_nx2.c >index 007192d..66d629e 100644 >--- a/drivers/scsi/qla2xxx/qla_nx2.c >+++ b/drivers/scsi/qla2xxx/qla_nx2.c >@@ -3491,7 +3491,7 @@ qla8044_poll_flash_status_reg(struct scsi_qla_host >*vha) > int retries =3D QLA8044_FLASH_READ_RETRY_COUNT; > int ret_val =3D QLA_SUCCESS; >=20 >- while (retries--) { >+ while (--retries) { > ret_val =3D qla8044_rd_reg_indirect(vha, QLA8044_FLASH_STATUS, > &flash_status); > if (ret_val) { There is flaw in this pre-decrement logic here for following 2 reasons 1. The pre-decrement reduces the total number of retries by one 2. If the retries is already Zero, then the pre-decrement would cause loop to iterate for a very large number of times. The correct fix for this would be to change the if(!retries) to if (retries =3D -1) or if (retries < 0) We=B9ll send a follow up patch to fix this. Thanks, Himanshu >-- >To unsubscribe from this list: send the line "unsubscribe linux-scsi" in >the body of a message to majordomo@vger.kernel.org >More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html