Date:   Thu, 28 Mar 2019 14:23:20 -0700
From:   Matthias Kaehlcke <mka@chromium.org>
To:     kbuild test robot <lkp@intel.com>
Cc:     Harish Bandi <c-hbandi@codeaurora.org>, kbuild-all@01.org,
        marcel@holtmann.org, johan.hedberg@gmail.com,
        linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org,
        hemantg@codeaurora.org, linux-arm-msm@vger.kernel.org,
        bgodavar@codeaurora.org, anubhavg@codeaurora.org,
        devicetree@vger.kernel.org, mark.rutland@arm.com,
        robh+dt@kernel.org
Subject: Re: [PATCH v6 1/2] Bluetooth: hci_qca: Added support for WCN3998
Message-ID: <20190328212320.GF112750@google.com>
References: <1553689723-21017-2-git-send-email-c-hbandi@codeaurora.org>
 <201903290535.u5TF12SC%lkp@intel.com>
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Sender: linux-bluetooth-owner@vger.kernel.org
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On Fri, Mar 29, 2019 at 05:05:49AM +0800, kbuild test robot wrote:
> Hi Harish,
> 
> Thank you for the patch! Perhaps something to improve:
> 
> [auto build test WARNING on bluetooth-next/master]
> [also build test WARNING on next-20190328]
> [cannot apply to v5.1-rc2]
> [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
> 
> url:    https://github.com/0day-ci/linux/commits/Harish-Bandi/Bluetooth-hci_qca-Added-support-for-WCN3998/20190328-213357
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next.git master
> config: riscv-allmodconfig (attached as .config)
> compiler: riscv64-linux-gcc (GCC) 8.1.0
> reproduce:
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # save the attached .config to linux build tree
>         GCC_VERSION=8.1.0 make.cross ARCH=riscv 
> 
> Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
> http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings
> 
> All warnings (new ones prefixed by >>):
> 
>    drivers/bluetooth/btqca.c: In function 'qca_uart_setup':
> >> drivers/bluetooth/btqca.c:369:3: warning: 'rom_ver' may be used uninitialized in this function [-Wmaybe-uninitialized]
>       snprintf(config.fwname, sizeof(config.fwname),
>       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>         "qca/crnv%02x.bin", rom_ver);
>         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> vim +/rom_ver +369 drivers/bluetooth/btqca.c
> 
> 83e81961 Ben Young Tae Kim      2015-08-10  333  
> aadebac4 Balakrishna Godavarthi 2018-08-03  334  int qca_uart_setup(struct hci_dev *hdev, uint8_t baudrate,
> aadebac4 Balakrishna Godavarthi 2018-08-03  335  		   enum qca_btsoc_type soc_type, u32 soc_ver)
> 83e81961 Ben Young Tae Kim      2015-08-10  336  {
> 83e81961 Ben Young Tae Kim      2015-08-10  337  	struct rome_config config;
> 83e81961 Ben Young Tae Kim      2015-08-10  338  	int err;
> 4219d468 Balakrishna Godavarthi 2018-08-03  339  	u8 rom_ver;

With the use of qca_is_wcn399x() the compiler can't determine anymore
that rom_ver is only read for WCN399x, in which case it is also
initialized. Just initialize rom_ver with 0 to keep the compiler happy.

> 83e81961 Ben Young Tae Kim      2015-08-10  340  
> ba493d4f Balakrishna Godavarthi 2018-08-03  341  	bt_dev_dbg(hdev, "QCA setup on UART");
> 83e81961 Ben Young Tae Kim      2015-08-10  342  
> 83e81961 Ben Young Tae Kim      2015-08-10  343  	config.user_baud_rate = baudrate;
> 83e81961 Ben Young Tae Kim      2015-08-10  344  
> 83e81961 Ben Young Tae Kim      2015-08-10  345  	/* Download rampatch file */
> 83e81961 Ben Young Tae Kim      2015-08-10  346  	config.type = TLV_TYPE_PATCH;
> cc8a70bd Harish Bandi           2019-03-27  347  	if (qca_is_wcn399x(soc_type)) {
> 4219d468 Balakrishna Godavarthi 2018-08-03  348  		/* Firmware files to download are based on ROM version.
> 4219d468 Balakrishna Godavarthi 2018-08-03  349  		 * ROM version is derived from last two bytes of soc_ver.
> 4219d468 Balakrishna Godavarthi 2018-08-03  350  		 */
> 4219d468 Balakrishna Godavarthi 2018-08-03  351  		rom_ver = ((soc_ver & 0x00000f00) >> 0x04) |
> 4219d468 Balakrishna Godavarthi 2018-08-03  352  			    (soc_ver & 0x0000000f);
> 4219d468 Balakrishna Godavarthi 2018-08-03  353  		snprintf(config.fwname, sizeof(config.fwname),
> 4219d468 Balakrishna Godavarthi 2018-08-03  354  			 "qca/crbtfw%02x.tlv", rom_ver);
> 4219d468 Balakrishna Godavarthi 2018-08-03  355  	} else {
> 4219d468 Balakrishna Godavarthi 2018-08-03  356  		snprintf(config.fwname, sizeof(config.fwname),
> 4219d468 Balakrishna Godavarthi 2018-08-03  357  			 "qca/rampatch_%08x.bin", soc_ver);
> 4219d468 Balakrishna Godavarthi 2018-08-03  358  	}
> 4219d468 Balakrishna Godavarthi 2018-08-03  359  
> ba493d4f Balakrishna Godavarthi 2018-08-03  360  	err = qca_download_firmware(hdev, &config);
> 83e81961 Ben Young Tae Kim      2015-08-10  361  	if (err < 0) {
> ba493d4f Balakrishna Godavarthi 2018-08-03  362  		bt_dev_err(hdev, "QCA Failed to download patch (%d)", err);
> 83e81961 Ben Young Tae Kim      2015-08-10  363  		return err;
> 83e81961 Ben Young Tae Kim      2015-08-10  364  	}
> 83e81961 Ben Young Tae Kim      2015-08-10  365  
> 83e81961 Ben Young Tae Kim      2015-08-10  366  	/* Download NVM configuration */
> 83e81961 Ben Young Tae Kim      2015-08-10  367  	config.type = TLV_TYPE_NVM;
> cc8a70bd Harish Bandi           2019-03-27  368  	if (qca_is_wcn399x(soc_type))
> 4219d468 Balakrishna Godavarthi 2018-08-03 @369  		snprintf(config.fwname, sizeof(config.fwname),
> 4219d468 Balakrishna Godavarthi 2018-08-03  370  			 "qca/crnv%02x.bin", rom_ver);
> 4219d468 Balakrishna Godavarthi 2018-08-03  371  	else
> 4219d468 Balakrishna Godavarthi 2018-08-03  372  		snprintf(config.fwname, sizeof(config.fwname),
> 4219d468 Balakrishna Godavarthi 2018-08-03  373  			 "qca/nvm_%08x.bin", soc_ver);
> 4219d468 Balakrishna Godavarthi 2018-08-03  374  
> ba493d4f Balakrishna Godavarthi 2018-08-03  375  	err = qca_download_firmware(hdev, &config);
> 83e81961 Ben Young Tae Kim      2015-08-10  376  	if (err < 0) {
> ba493d4f Balakrishna Godavarthi 2018-08-03  377  		bt_dev_err(hdev, "QCA Failed to download NVM (%d)", err);
> 83e81961 Ben Young Tae Kim      2015-08-10  378  		return err;
> 83e81961 Ben Young Tae Kim      2015-08-10  379  	}
> 83e81961 Ben Young Tae Kim      2015-08-10  380  
> 83e81961 Ben Young Tae Kim      2015-08-10  381  	/* Perform HCI reset */
> ba493d4f Balakrishna Godavarthi 2018-08-03  382  	err = qca_send_reset(hdev);
> 83e81961 Ben Young Tae Kim      2015-08-10  383  	if (err < 0) {
> ba493d4f Balakrishna Godavarthi 2018-08-03  384  		bt_dev_err(hdev, "QCA Failed to run HCI_RESET (%d)", err);
> 83e81961 Ben Young Tae Kim      2015-08-10  385  		return err;
> 83e81961 Ben Young Tae Kim      2015-08-10  386  	}
> 83e81961 Ben Young Tae Kim      2015-08-10  387  
> ba493d4f Balakrishna Godavarthi 2018-08-03  388  	bt_dev_info(hdev, "QCA setup on UART is completed");
> 83e81961 Ben Young Tae Kim      2015-08-10  389  
> 83e81961 Ben Young Tae Kim      2015-08-10  390  	return 0;
> 83e81961 Ben Young Tae Kim      2015-08-10  391  }
> ba493d4f Balakrishna Godavarthi 2018-08-03  392  EXPORT_SYMBOL_GPL(qca_uart_setup);
> 83e81961 Ben Young Tae Kim      2015-08-10  393  
> 
> :::::: The code at line 369 was first introduced by commit
> :::::: 4219d4686875fdd83df3da00fda5ff0551e0a2d7 Bluetooth: btqca: Add wcn3990 firmware download support.
> 
> :::::: TO: Balakrishna Godavarthi <bgodavar@codeaurora.org>
> :::::: CC: Marcel Holtmann <marcel@holtmann.org>
> 
> ---
> 0-DAY kernel test infrastructure                Open Source Technology Center
> https://lists.01.org/pipermail/kbuild-all                   Intel Corporation