RE: drivers/net/wireless/realtek/rtw88/mac.c:748 __rtw_download_firmware() warn: missing unwind goto?

[Ping-Ke Shih <pkshih@xxxxxxxxxxx>]

> -----Original Message-----
> From: Kalle Valo <kvalo@xxxxxxxxxx>
> Sent: Tuesday, June 6, 2023 9:34 PM
> To: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Cc: oe-kbuild@xxxxxxxxxxxxxxx; Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>; lkp@xxxxxxxxx;
> oe-kbuild-all@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-wireless@xxxxxxxxxxxxxxx
> Subject: Re: drivers/net/wireless/realtek/rtw88/mac.c:748 __rtw_download_firmware() warn: missing unwind
> goto?
> 
> Adding linux-wireless, top posting so that the whole report is included.
> 
> Dan Carpenter <dan.carpenter@xxxxxxxxxx> writes:
> 
> > Hi Sascha,
> >
> > First bad commit (maybe != root cause):
> >
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > head:   9561de3a55bed6bdd44a12820ba81ec416e705a7
> > commit: 45794099f5e1d7abc5eb07e6eec7e1e5c6cb540d wifi: rtw88: Add
> > rtw8822bu chipset support
> > config: riscv-randconfig-m031-20230605
> > (https://download.01.org/0day-ci/archive/20230605/202306052310.OVhcUjZ3-lkp@xxxxxxxxx/config)
> > compiler: riscv64-linux-gcc (GCC) 12.3.0
> >
> > If you fix the issue, kindly add following tag where applicable
> > | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > | Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> > | Closes: https://lore.kernel.org/r/202306052310.OVhcUjZ3-lkp@xxxxxxxxx/
> >
> > smatch warnings:
> > drivers/net/wireless/realtek/rtw88/mac.c:748 __rtw_download_firmware()
> > warn: missing unwind goto?
> >
> > vim +748 drivers/net/wireless/realtek/rtw88/mac.c
> >
> > 3d8bf50860c7de Yan-Hsuan Chuang 2020-04-24 717 static int
> > __rtw_download_firmware(struct rtw_dev *rtwdev,
> > 3d8bf50860c7de Yan-Hsuan Chuang 2020-04-24 718 struct rtw_fw_state
> > *fw)
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26  719  {
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26 720 struct rtw_backup_info
> > bckp[DLFW_RESTORE_REG_NUM];
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26 721 const u8 *data =
> > fw->firmware->data;
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26  722       u32 size = fw->firmware->size;
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26  723       u32 ltecoex_bckp;
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26  724       int ret;
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26  725
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26 726 if
> > (!check_firmware_size(data, size))
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26  727               return -EINVAL;
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26  728
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26 729 if
> > (!ltecoex_read_reg(rtwdev, 0x38, &ltecoex_bckp))
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26  730               return -EBUSY;
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26  731
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26 732 wlan_cpu_enable(rtwdev,
> > false);
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26  733
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26 734
> > download_firmware_reg_backup(rtwdev, bckp);
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26 735
> > download_firmware_reset_platform(rtwdev);
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26  736
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26 737 ret =
> > start_download_firmware(rtwdev, data, size);
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26  738       if (ret)
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26  739               goto dlfw_fail;
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26  740
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26 741
> > download_firmware_reg_restore(rtwdev, bckp, DLFW_RESTORE_REG_NUM);
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26  742
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26 743
> > download_firmware_end_flow(rtwdev);
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26  744
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26  745       wlan_cpu_enable(rtwdev, true);
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26  746
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26 747 if
> > (!ltecoex_reg_write(rtwdev, 0x38, ltecoex_bckp))
> > e3037485c68ec1 Yan-Hsuan Chuang 2019-04-26 @748               return -EBUSY;
> >
> > All the other error paths goto dlfw_fail;

At this point, the things of 'dlfw_fail:' have been done by
download_firmware_end_flow() and wlan_cpu_enable() at L743 and L745 normally. 
An exception is download_firmware_end_flow() clear BIT_MCUFWDL_EN bit conditionally,
so I think it would be better to goto dlfw_fail. 

I can make a patch for this.

Ping-Ke