From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nilesh Javali Subject: Re: [PATCH 5/7] scsi: qla4xxx: shut up warning for rd_reg_indirect Date: Mon, 1 Feb 2016 08:17:48 +0000 Message-ID: References: <1453910247-3447628-1-git-send-email-arnd@arndb.de> <1453910247-3447628-6-git-send-email-arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Return-path: In-Reply-To: <1453910247-3447628-6-git-send-email-arnd@arndb.de> Content-Language: en-US Content-ID: <618D1F2A08DBE04C96EE41CC04D050D6@namprd11.prod.outlook.com> Sender: linux-kernel-owner@vger.kernel.org To: Arnd Bergmann , "Martin K. Petersen" , "James.Bottomley@HansenPartnership.com" Cc: "linux-arm-kernel@lists.infradead.org" , linux-scsi , "James E.J. Bottomley" , Dept-Eng QLogic Storage Upstream , linux-kernel List-Id: linux-scsi@vger.kernel.org On 27/01/16 9:27 PM, "Arnd Bergmann" wrote: >The qla4_83xx_rd_reg_indirect() function can fail when it is unable >to read a register, but not all callers check its return value before >using the register data, and gcc correctly warns about this: > >qla4xxx/ql4_83xx.c: In function 'qla4_83xx_process_reset_template': >qla4xxx/ql4_83xx.c:1073:36: warning: 'value' may be used uninitialized in >this function > ha->reset_tmplt.array[index++] = value; > ^ >qla4xxx/ql4_83xx.c:1050:11: note: 'value' was declared here > uint32_t value; > ^ >qla4xxx/ql4_83xx.c:902:8: warning: 'value' may be used uninitialized in >this function > value &= p_rmw_hdr->test_mask; > ^ >qla4xxx/ql4_83xx.c:895:11: note: 'value' was declared here > uint32_t value; > ^ >In file included from ../include/linux/io.h:25:0, > from ../include/linux/pci.h:31, > from ../drivers/scsi/qla4xxx/ql4_def.h:16, > from ../drivers/scsi/qla4xxx/ql4_83xx.c:10: >asm/io.h:101:2: warning: 'value' may be used uninitialized in this >function > asm volatile("str %1, %0" > ^ >qla4xxx/ql4_83xx.c:874:11: note: 'value' was declared here > uint32_t value; > ^ > >Unfortunately, I don't see any helpful way to add proper error handling >for this case, and the failure scenario for rd_reg seems rather obscure, >so this bails out and makes the rd_reg accessor set the result to >0xffffffff >so we at least get a predictable value. > >Signed-off-by: Arnd Bergmann >--- > drivers/scsi/qla4xxx/ql4_83xx.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > >diff --git a/drivers/scsi/qla4xxx/ql4_83xx.c >b/drivers/scsi/qla4xxx/ql4_83xx.c >index 5d4f8e67fb25..638f72c5ab05 100644 >--- a/drivers/scsi/qla4xxx/ql4_83xx.c >+++ b/drivers/scsi/qla4xxx/ql4_83xx.c >@@ -46,11 +46,13 @@ int qla4_83xx_rd_reg_indirect(struct scsi_qla_host >*ha, uint32_t addr, > > ret_val = qla4_83xx_set_win_base(ha, addr); > >- if (ret_val == QLA_SUCCESS) >+ if (ret_val == QLA_SUCCESS) { > *data = qla4_83xx_rd_reg(ha, QLA83XX_WILDCARD); >- else >+ } else { >+ *data = 0xffffffff; > ql4_printk(KERN_ERR, ha, "%s: failed read of addr 0x%x!\n", > __func__, addr); >+ } > > return ret_val; > } >-- >2.7.0 > Acked-by: Nilesh Javali