Re: [PATCH v5] usb: dwc3: debugfs: Prevent any register access when devices

[kernel test robot <error27@gmail.com>]

Hi Udipto,

kernel test robot noticed the following build warnings:

[auto build test WARNING on usb/usb-testing]
[also build test WARNING on usb/usb-next usb/usb-linus driver-core/driver-core-testing driver-core/driver-core-next driver-core/driver-core-linus westeri-thunderbolt/next linus/master v6.3-rc7 next-20230418]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Udipto-Goswami/usb-dwc3-debugfs-Prevent-any-register-access-when-devices/20230418-202039
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
patch link:    https://lore.kernel.org/r/20230418121835.17550-1-quic_ugoswami%40quicinc.com
patch subject: [PATCH v5] usb: dwc3: debugfs: Prevent any register access when devices
config: x86_64-randconfig-m001 (https://download.01.org/0day-ci/archive/20230419/202304191354.gk7ee6Gf-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <error27@gmail.com>
| Link: https://lore.kernel.org/r/202304191354.gk7ee6Gf-lkp@intel.com/

smatch warnings:
drivers/usb/dwc3/debugfs.c:338 dwc3_lsp_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:409 dwc3_mode_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:485 dwc3_testmode_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:555 dwc3_testmode_write() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:586 dwc3_link_state_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:649 dwc3_link_state_write() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:702 dwc3_tx_fifo_size_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:732 dwc3_rx_fifo_size_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:761 dwc3_tx_request_queue_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:784 dwc3_rx_request_queue_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:807 dwc3_rx_info_queue_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:830 dwc3_descriptor_fetch_queue_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:853 dwc3_event_queue_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:911 dwc3_trb_ring_show() warn: pm_runtime_get_sync() also returns 1 on success
drivers/usb/dwc3/debugfs.c:960 dwc3_ep_info_register_show() warn: pm_runtime_get_sync() also returns 1 on success

vim +338 drivers/usb/dwc3/debugfs.c

62ba09d6bb6330 Thinh Nguyen              2018-11-07  329  static int dwc3_lsp_show(struct seq_file *s, void *unused)
62ba09d6bb6330 Thinh Nguyen              2018-11-07  330  {
62ba09d6bb6330 Thinh Nguyen              2018-11-07  331  	struct dwc3		*dwc = s->private;
62ba09d6bb6330 Thinh Nguyen              2018-11-07  332  	unsigned int		current_mode;
62ba09d6bb6330 Thinh Nguyen              2018-11-07  333  	unsigned long		flags;
62ba09d6bb6330 Thinh Nguyen              2018-11-07  334  	u32			reg;
86f75fd9ae2609 Udipto Goswami            2023-04-18  335  	int			ret;
86f75fd9ae2609 Udipto Goswami            2023-04-18  336  
86f75fd9ae2609 Udipto Goswami            2023-04-18  337  	ret = pm_runtime_get_sync(dwc->dev);
86f75fd9ae2609 Udipto Goswami            2023-04-18 @338  	if (!ret || ret < 0) {
86f75fd9ae2609 Udipto Goswami            2023-04-18  339  		pm_runtime_put(dwc->dev);
86f75fd9ae2609 Udipto Goswami            2023-04-18  340  		return 0;

I don't know what's going on here, but Smatch doesn't like it.  :P

86f75fd9ae2609 Udipto Goswami            2023-04-18  341  	}
62ba09d6bb6330 Thinh Nguyen              2018-11-07  342  
62ba09d6bb6330 Thinh Nguyen              2018-11-07  343  	spin_lock_irqsave(&dwc->lock, flags);
62ba09d6bb6330 Thinh Nguyen              2018-11-07  344  	reg = dwc3_readl(dwc->regs, DWC3_GSTS);
62ba09d6bb6330 Thinh Nguyen              2018-11-07  345  	current_mode = DWC3_GSTS_CURMOD(reg);
62ba09d6bb6330 Thinh Nguyen              2018-11-07  346  
62ba09d6bb6330 Thinh Nguyen              2018-11-07  347  	switch (current_mode) {
62ba09d6bb6330 Thinh Nguyen              2018-11-07  348  	case DWC3_GSTS_CURMOD_HOST:
62ba09d6bb6330 Thinh Nguyen              2018-11-07  349  		dwc3_host_lsp(s);
62ba09d6bb6330 Thinh Nguyen              2018-11-07  350  		break;
62ba09d6bb6330 Thinh Nguyen              2018-11-07  351  	case DWC3_GSTS_CURMOD_DEVICE:
62ba09d6bb6330 Thinh Nguyen              2018-11-07  352  		dwc3_gadget_lsp(s);
62ba09d6bb6330 Thinh Nguyen              2018-11-07  353  		break;
62ba09d6bb6330 Thinh Nguyen              2018-11-07  354  	default:
62ba09d6bb6330 Thinh Nguyen              2018-11-07  355  		seq_puts(s, "Mode is unknown, no LSP register printed\n");
62ba09d6bb6330 Thinh Nguyen              2018-11-07  356  		break;
62ba09d6bb6330 Thinh Nguyen              2018-11-07  357  	}
62ba09d6bb6330 Thinh Nguyen              2018-11-07  358  	spin_unlock_irqrestore(&dwc->lock, flags);
86f75fd9ae2609 Udipto Goswami            2023-04-18  359  	pm_runtime_put(dwc->dev);
62ba09d6bb6330 Thinh Nguyen              2018-11-07  360  
62ba09d6bb6330 Thinh Nguyen              2018-11-07  361  	return 0;
62ba09d6bb6330 Thinh Nguyen              2018-11-07  362  }

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