Re: drivers/media/pci/intel/ipu-bridge.c:752 ipu_bridge_ivsc_is_ready() warn: iterator 'i' not incremented

[Sakari Ailus <sakari.ailus@iki.fi>]

Hi Ricardo,

On Fri, Nov 22, 2024 at 09:06:40AM +0100, Ricardo Ribalda wrote:
> Hi
> 
> On Fri, 22 Nov 2024 at 09:01, Sakari Ailus <sakari.ailus@linux.intel.com> wrote:
> >
> > Hi Dan,
> >
> > On Fri, Nov 22, 2024 at 10:45:53AM +0300, Dan Carpenter wrote:
> > > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > > head:   28eb75e178d389d325f1666e422bc13bbbb9804c
> > > commit: 93da10eee90b2ffa4b496dd4a6ea276c57461fb6 media: intel/ipu6: Fix direct dependency Kconfig error
> > > config: alpha-randconfig-r072-20241122 (https://download.01.org/0day-ci/archive/20241122/202411221147.N6w23gDo-lkp@intel.com/config)
> > > compiler: alpha-linux-gcc (GCC) 14.2.0
> > >
> > > 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 <dan.carpenter@linaro.org>
> > > | Closes: https://lore.kernel.org/r/202411221147.N6w23gDo-lkp@intel.com/
> > >
> > > smatch warnings:
> > > drivers/media/pci/intel/ipu-bridge.c:752 ipu_bridge_ivsc_is_ready() warn: iterator 'i' not incremented
> > >
> > > vim +/i +752 drivers/media/pci/intel/ipu-bridge.c
> > >
> > > c66821f381aed2 drivers/media/pci/intel/ipu-bridge.c       Wentong Wu      2023-08-03  745  static int ipu_bridge_ivsc_is_ready(void)
> > > c66821f381aed2 drivers/media/pci/intel/ipu-bridge.c       Wentong Wu      2023-08-03  746  {
> > > c66821f381aed2 drivers/media/pci/intel/ipu-bridge.c       Wentong Wu      2023-08-03  747     struct acpi_device *sensor_adev, *adev;
> > > c66821f381aed2 drivers/media/pci/intel/ipu-bridge.c       Wentong Wu      2023-08-03  748     struct device *csi_dev;
> > > c66821f381aed2 drivers/media/pci/intel/ipu-bridge.c       Wentong Wu      2023-08-03  749     bool ready = true;
> > > c66821f381aed2 drivers/media/pci/intel/ipu-bridge.c       Wentong Wu      2023-08-03  750     unsigned int i;
> > > c66821f381aed2 drivers/media/pci/intel/ipu-bridge.c       Wentong Wu      2023-08-03  751
> > > c66821f381aed2 drivers/media/pci/intel/ipu-bridge.c       Wentong Wu      2023-08-03 @752     for (i = 0; i < ARRAY_SIZE(ipu_supported_sensors); i++) {
> > > 8810e055b57543 drivers/media/pci/intel/ipu-bridge.c       Ricardo Ribalda 2024-05-01  753  #if IS_ENABLED(CONFIG_ACPI)
> > > c66821f381aed2 drivers/media/pci/intel/ipu-bridge.c       Wentong Wu      2023-08-03  754             const struct ipu_sensor_config *cfg =
> > > c66821f381aed2 drivers/media/pci/intel/ipu-bridge.c       Wentong Wu      2023-08-03  755                     &ipu_supported_sensors[i];
> > > c66821f381aed2 drivers/media/pci/intel/ipu-bridge.c       Wentong Wu      2023-08-03  756
> > > c66821f381aed2 drivers/media/pci/intel/ipu-bridge.c       Wentong Wu      2023-08-03  757             for_each_acpi_dev_match(sensor_adev, cfg->hid, NULL, -1) {
> > > 8810e055b57543 drivers/media/pci/intel/ipu-bridge.c       Ricardo Ribalda 2024-05-01  758  #else
> > > 8810e055b57543 drivers/media/pci/intel/ipu-bridge.c       Ricardo Ribalda 2024-05-01  759             while (true) {
> > >                                                                                                         ^^^^^^^^^^^^^^
> > >
> > > 8810e055b57543 drivers/media/pci/intel/ipu-bridge.c       Ricardo Ribalda 2024-05-01  760                     sensor_adev = NULL;
> > > 8810e055b57543 drivers/media/pci/intel/ipu-bridge.c       Ricardo Ribalda 2024-05-01  761  #endif
> > > 8810e055b57543 drivers/media/pci/intel/ipu-bridge.c       Ricardo Ribalda 2024-05-01  762                     if (!ACPI_PTR(sensor_adev->status.enabled))
> > > c66821f381aed2 drivers/media/pci/intel/ipu-bridge.c       Wentong Wu      2023-08-03  763                             continue;
> > >
> > >
> > > These continues make sense in for_each_acpi_dev_match() but not in a while (true) {
> > > loop.  We're stuck forever.
> >
> > The non-ACPI case is there just for the looks... I think what should be
> > done is to make the entire loop conditional to CONFIG_ACPI. I can post a
> > patch.
> 
> I saw your mail after I sent my patch :)
> https://patchwork.linuxtv.org/project/linux-media/patch/20241122-fix-ipu-v1-1-246e254cb77c@chromium.org/
> 
> If we make the entire loop conditional then we would not compile test the
> loop.

I'm fine with the patch as such but don't you think we might get just a
different warning from this one? :-) I'm fine trying this though.

-- 
Sakari Ailus