On 21/03/15 05:07PM, Leon Romanovsky wrote: > On Mon, Mar 15, 2021 at 08:34:09AM -0600, Alex Williamson wrote: > > On Mon, 15 Mar 2021 14:52:26 +0100 > > Pali Rohár <pali@xxxxxxxxxx> wrote: > > > > > On Monday 15 March 2021 19:13:23 Amey Narkhede wrote: > > > > slot reset (pci_dev_reset_slot_function) and secondary bus > > > > reset(pci_parent_bus_reset) which I think are hot reset and > > > > warm reset respectively. > > > > > > No. PCI secondary bus reset = PCIe Hot Reset. Slot reset is just another > > > type of reset, which is currently implemented only for PCIe hot plug > > > bridges and for PowerPC PowerNV platform and it just call PCI secondary > > > bus reset with some other hook. PCIe Warm Reset does not have API in > > > kernel and therefore drivers do not export this type of reset via any > > > kernel function (yet). > > > > Warm reset is beyond the scope of this series, but could be implemented > > in a compatible way to fit within the pci_reset_fn_methods[] array > > defined here. Note that with this series the resets available through > > pci_reset_function() and the per device reset attribute is sysfs remain > > exactly the same as they are currently. The bus and slot reset > > methods used here are limited to devices where only a single function is > > affected by the reset, therefore it is not like the patch you proposed > > which performed a reset irrespective of the downstream devices. This > > series only enables selection of the existing methods. Thanks, > > Alex, > > I asked the patch author here [1], but didn't get any response, maybe > you can answer me. What is the use case scenario for this functionality? > > Thanks > > [1] https://lore.kernel.org/lkml/YE389lAqjJSeTolM@unreal > Sorry for not responding immediately. There were some buggy wifi cards which needed FLR explicitly not sure if that behavior is fixed in drivers. Also there is use a case at Nutanix but the engineer who is involved is on PTO that is why I did not respond immediately as I don't know the details yet. Thanks, Amey
