Re: [PATCH net-next v22 1/2] mailbox/pcc: support mailbox management of the shared buffer

[kernel test robot <lkp@intel.com>]

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Hi,

kernel test robot noticed the following build warnings:

[auto build test WARNING on net-next/main]

url:    https://github.com/intel-lab-lkp/linux/commits/admiyo-os-amperecomputing-com/mailbox-pcc-support-mailbox-management-of-the-shared-buffer/20250711-031525
base:   net-next/main
patch link:    https://lore.kernel.org/r/20250710191209.737167-2-admiyo%40os.amperecomputing.com
patch subject: [PATCH net-next v22 1/2] mailbox/pcc: support mailbox management of the shared buffer
:::::: branch date: 27 hours ago
:::::: commit date: 27 hours ago
config: x86_64-randconfig-161-20250711 (https://download.01.org/0day-ci/archive/20250712/202507120609.Myazax08-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <error27@gmail.com>
| Closes: https://lore.kernel.org/r/202507120609.Myazax08-lkp@intel.com/

smatch warnings:
drivers/mailbox/pcc.c:498 pcc_send_data() error: uninitialized symbol 'ret'.

vim +/ret +498 drivers/mailbox/pcc.c

e332edef98ddac Adam Young         2025-07-10  476  
e332edef98ddac Adam Young         2025-07-10  477  
86c22f8c9a3b71 Ashwin Chaugule    2014-11-12  478  /**
33350e6b1833b1 Ashwin Chaugule    2015-01-27  479   * pcc_send_data - Called from Mailbox Controller code. Used
33350e6b1833b1 Ashwin Chaugule    2015-01-27  480   *		here only to ring the channel doorbell. The PCC client
33350e6b1833b1 Ashwin Chaugule    2015-01-27  481   *		specific read/write is done in the client driver in
33350e6b1833b1 Ashwin Chaugule    2015-01-27  482   *		order to maintain atomicity over PCC channel once
33350e6b1833b1 Ashwin Chaugule    2015-01-27  483   *		OS has control over it. See above for flow of operations.
86c22f8c9a3b71 Ashwin Chaugule    2014-11-12  484   * @chan: Pointer to Mailbox channel over which to send data.
33350e6b1833b1 Ashwin Chaugule    2015-01-27  485   * @data: Client specific data written over channel. Used here
33350e6b1833b1 Ashwin Chaugule    2015-01-27  486   *		only for debug after PCC transaction completes.
86c22f8c9a3b71 Ashwin Chaugule    2014-11-12  487   *
86c22f8c9a3b71 Ashwin Chaugule    2014-11-12  488   * Return: Err if something failed else 0 for success.
86c22f8c9a3b71 Ashwin Chaugule    2014-11-12  489   */
86c22f8c9a3b71 Ashwin Chaugule    2014-11-12  490  static int pcc_send_data(struct mbox_chan *chan, void *data)
86c22f8c9a3b71 Ashwin Chaugule    2014-11-12  491  {
c45ded7e11352d Sudeep Holla       2021-09-17  492  	int ret;
bf18123e78f4d1 Sudeep Holla       2021-09-17  493  	struct pcc_chan_info *pchan = chan->con_priv;
e332edef98ddac Adam Young         2025-07-10  494  	struct acpi_pcct_ext_pcc_shared_memory __iomem *pcc_hdr;
e332edef98ddac Adam Young         2025-07-10  495  
e332edef98ddac Adam Young         2025-07-10  496  	if (pchan->chan.rx_alloc)
e332edef98ddac Adam Young         2025-07-10  497  		ret = pcc_write_to_buffer(chan, data);
e332edef98ddac Adam Young         2025-07-10 @498  	if (ret)
e332edef98ddac Adam Young         2025-07-10  499  		return ret;
8b0f57889843af Prakash, Prashanth 2016-02-17  500  
c45ded7e11352d Sudeep Holla       2021-09-17  501  	ret = pcc_chan_reg_read_modify_write(&pchan->cmd_update);
c45ded7e11352d Sudeep Holla       2021-09-17  502  	if (ret)
c45ded7e11352d Sudeep Holla       2021-09-17  503  		return ret;
c45ded7e11352d Sudeep Holla       2021-09-17  504  
e332edef98ddac Adam Young         2025-07-10  505  	pcc_hdr = pchan->chan.shmem;
e332edef98ddac Adam Young         2025-07-10  506  	if (ioread32(&pcc_hdr->flags) & PCC_CMD_COMPLETION_NOTIFY)
e332edef98ddac Adam Young         2025-07-10  507  		pchan->chan.irq_ack = true;
e332edef98ddac Adam Young         2025-07-10  508  
3db174e478cb0b Huisong Li         2023-08-01  509  	ret = pcc_chan_reg_read_modify_write(&pchan->db);
e332edef98ddac Adam Young         2025-07-10  510  
3db174e478cb0b Huisong Li         2023-08-01  511  	if (!ret && pchan->plat_irq > 0)
3db174e478cb0b Huisong Li         2023-08-01  512  		pchan->chan_in_use = true;
3db174e478cb0b Huisong Li         2023-08-01  513  
3db174e478cb0b Huisong Li         2023-08-01  514  	return ret;
86c22f8c9a3b71 Ashwin Chaugule    2014-11-12  515  }
86c22f8c9a3b71 Ashwin Chaugule    2014-11-12  516  

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