Messages in this thread | | | Subject | Re: [RFC PATCH v2] PCI/portdrv: Only disable Bus Master on kexec reboot and connected PCI devices | From | Tiezhu Yang <> | Date | Mon, 14 Sep 2020 14:30:29 +0800 |
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On 09/14/2020 02:13 PM, Tiezhu Yang wrote: > On 09/14/2020 12:06 PM, Lukas Wunner wrote: >> On Mon, Sep 14, 2020 at 04:29:10AM +0800, Tiezhu Yang wrote: >>> --- a/drivers/pci/pcie/portdrv_pci.c >>> +++ b/drivers/pci/pcie/portdrv_pci.c >>> @@ -143,6 +144,28 @@ static void pcie_portdrv_remove(struct pci_dev >>> *dev) >>> } >>> pcie_port_device_remove(dev); >>> + pci_disable_device(dev); >>> +} >>> + >>> +static void pcie_portdrv_shutdown(struct pci_dev *dev) >>> +{ >>> + if (pci_bridge_d3_possible(dev)) { >>> + pm_runtime_forbid(&dev->dev); >>> + pm_runtime_get_noresume(&dev->dev); >>> + pm_runtime_dont_use_autosuspend(&dev->dev); >>> + } >>> + >>> + pcie_port_device_remove(dev); >>> + >>> + /* >>> + * If this is a kexec reboot, turn off Bus Master bit on the >>> + * device to tell it to not continue to do DMA. Don't touch >>> + * devices in D3cold or unknown states. >>> + * If it is not a kexec reboot, firmware will hit the PCI >>> + * devices with big hammer and stop their DMA any way. >>> + */ >>> + if (kexec_in_progress && (dev->current_state <= PCI_D3hot)) >>> + pci_disable_device(dev); >> The last portion of this function is already executed afterwards by >> pci_device_shutdown(). You don't need to duplicate it here: >> >> device_shutdown() >> dev->bus->shutdown() == pci_device_shutdown() >> drv->shutdown() == pcie_portdrv_shutdown() >> pci_disable_device() >> pci_disable_device() > > pcie_port_device_remove() deletes pci_disable_device(dev) at the > beginning of this patch.
Sorry, I misunderstood your meaning, you are right.
> > > diff > <https://lore.kernel.org/linux-pci/CAAhV-H5-X9OcBe3iRxF8PnKW-0j_10FVqm8cbiqW2-Lv4mTTdQ@mail.gmail.com/T/#iZ2e.:..:1600028950-10644-1-git-send-email-yangtiezhu::40loongson.cn:0drivers:pci:pcie:portdrv_core.c> > --git a/drivers/pci/pcie/portdrv_core.c > b/drivers/pci/pcie/portdrv_core.c index 50a9522..1991aca 100644 --- > a/drivers/pci/pcie/portdrv_core.c +++ > b/drivers/pci/pcie/portdrv_core.c @@ -491,7 +491,6 @@ void > pcie_port_device_remove(struct pci_dev *dev) { > device_for_each_child(&dev->dev, NULL, remove_iter); > pci_free_irq_vectors(dev); > - pci_disable_device(dev); } > >> >> Thanks, >> >> Lukas
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