Messages in this thread | | | Date | Wed, 4 Mar 2020 07:43:18 -0600 | From | Bjorn Helgaas <> | Subject | Re: [PATCH v4 05/10] PCI: Add pci_status_get_and_clear_errors |
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On Sat, Feb 29, 2020 at 11:24:23PM +0100, Heiner Kallweit wrote: > Several drivers use the following code sequence: > 1. Read PCI_STATUS > 2. Mask out non-error bits > 3. Action based on error bits set > 4. Write back set error bits to clear them > > As this is a repeated pattern, add a helper to the PCI core. > > Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Nit: if you have any reason to revise this, I would prefer "pci_status_get_and_clear_errors()" (with parens) in the subject.
> --- > v4: > - improve commit description > --- > drivers/pci/pci.c | 23 +++++++++++++++++++++++ > include/linux/pci.h | 1 + > 2 files changed, 24 insertions(+) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index d828ca835..c16b0ba2a 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -173,6 +173,29 @@ unsigned char pci_bus_max_busnr(struct pci_bus *bus) > } > EXPORT_SYMBOL_GPL(pci_bus_max_busnr); > > +/** > + * pci_status_get_and_clear_errors - return and clear error bits in PCI_STATUS > + * @pdev: the PCI device > + * > + * Returns error bits set in PCI_STATUS and clears them. > + */ > +int pci_status_get_and_clear_errors(struct pci_dev *pdev) > +{ > + u16 status; > + int ret; > + > + ret = pci_read_config_word(pdev, PCI_STATUS, &status); > + if (ret != PCIBIOS_SUCCESSFUL) > + return -EIO; > + > + status &= PCI_STATUS_ERROR_BITS; > + if (status) > + pci_write_config_word(pdev, PCI_STATUS, status); > + > + return status; > +} > +EXPORT_SYMBOL_GPL(pci_status_get_and_clear_errors); > + > #ifdef CONFIG_HAS_IOMEM > void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar) > { > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 101d71e0a..7beaf51e9 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -1210,6 +1210,7 @@ int pci_select_bars(struct pci_dev *dev, unsigned long flags); > bool pci_device_is_present(struct pci_dev *pdev); > void pci_ignore_hotplug(struct pci_dev *dev); > struct pci_dev *pci_real_dma_dev(struct pci_dev *dev); > +int pci_status_get_and_clear_errors(struct pci_dev *pdev); > > int __printf(6, 7) pci_request_irq(struct pci_dev *dev, unsigned int nr, > irq_handler_t handler, irq_handler_t thread_fn, void *dev_id, > -- > 2.25.1 > >
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