Re: [PATCH 3/7] thermal: int340x: processor_thermal: Use non MSI interrupts

[srinivas pandruvada <srinivas.pandruvada@linux.intel.com>]

On Wed, 2023-06-21 at 14:53 +0000, Zhang, Rui wrote:
> On Tue, 2023-06-20 at 16:01 -0700, Srinivas Pandruvada wrote:
> > There are issues in using MSI interrupts for processor thermal
> > device.
> > The support is not consistent, across generations. Even in the same
> > generation, there are issue in getting interrupts via MSI.
> > 
> > Hence always use legacy PCI interrupts by default, instead of MSI.
> > Add a module param to use of MSI, so that MSI can be still used.
> > 
> > Signed-off-by: Srinivas Pandruvada
> > <srinivas.pandruvada@linux.intel.com>
> > ---
> >  .../processor_thermal_device_pci.c            | 33 ++++++++++++---
> > --
> > --
> >  1 file changed, 22 insertions(+), 11 deletions(-)
> > 
> > diff --git
> > a/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pc
> > i.
> > c
> > b/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pc
> > i.
> > c
> > index 5a2bcfff0a68..057778f7bece 100644
> > ---
> > a/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pc
> > i.
> > c
> > +++
> > b/drivers/thermal/intel/int340x_thermal/processor_thermal_device_pc
> > i.
> > c
> > @@ -15,6 +15,11 @@
> >  
> >  #define DRV_NAME "proc_thermal_pci"
> >  
> > +static int msi_enabled;
> > +module_param(msi_enabled, int, 0644);
> 
> why not use
> 
> static bool msi_enabled;
> module_params(msi_enabled, bool, 0644);
> 
Sure.

Thanks,
Srinivas

> thanks,
> rui
> 
> > +MODULE_PARM_DESC(msi_enabled,
> > +       "Use PCI MSI based interrupts for processor thermal
> > device.");
> > +
> >  struct proc_thermal_pci {
> >         struct pci_dev *pdev;
> >         struct proc_thermal_device *proc_priv;
> > @@ -219,8 +224,6 @@ static int proc_thermal_pci_probe(struct
> > pci_dev
> > *pdev, const struct pci_device_
> >                 return ret;
> >         }
> >  
> > -       pci_set_master(pdev);
> > -
> >         INIT_DELAYED_WORK(&pci_info->work,
> > proc_thermal_threshold_work_fn);
> >  
> >         ret = proc_thermal_add(&pdev->dev, proc_priv);
> > @@ -248,16 +251,23 @@ static int proc_thermal_pci_probe(struct
> > pci_dev *pdev, const struct pci_device_
> >                 goto err_ret_mmio;
> >         }
> >  
> > -       /* request and enable interrupt */
> > -       ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);
> > -       if (ret < 0) {
> > -               dev_err(&pdev->dev, "Failed to allocate
> > vectors!\n");
> > -               goto err_ret_tzone;
> > -       }
> > -       if (!pdev->msi_enabled && !pdev->msix_enabled)
> > +       if (msi_enabled) {
> > +               pci_set_master(pdev);
> > +               /* request and enable interrupt */
> > +               ret = pci_alloc_irq_vectors(pdev, 1, 1,
> > PCI_IRQ_ALL_TYPES);
> > +               if (ret < 0) {
> > +                       dev_err(&pdev->dev, "Failed to allocate
> > vectors!\n");
> > +                       goto err_ret_tzone;
> > +               }
> > +               if (!pdev->msi_enabled && !pdev->msix_enabled)
> > +                       irq_flag = IRQF_SHARED;
> > +
> > +               irq =  pci_irq_vector(pdev, 0);
> > +       } else {
> >                 irq_flag = IRQF_SHARED;
> > +               irq = pdev->irq;
> > +       }
> >  
> > -       irq =  pci_irq_vector(pdev, 0);
> >         ret = devm_request_threaded_irq(&pdev->dev, irq,
> >                                         proc_thermal_irq_handler,
> > NULL,
> >                                         irq_flag, KBUILD_MODNAME,
> > pci_info);
> > @@ -273,7 +283,8 @@ static int proc_thermal_pci_probe(struct
> > pci_dev
> > *pdev, const struct pci_device_
> >         return 0;
> >  
> >  err_free_vectors:
> > -       pci_free_irq_vectors(pdev);
> > +       if (msi_enabled)
> > +               pci_free_irq_vectors(pdev);
> >  err_ret_tzone:
> >         thermal_zone_device_unregister(pci_info->tzone);
> >  err_ret_mmio:
>