Subject: [PATCH v2 2/2] PCI/ERR: Add reset support for non fatal errors

From: Kuppuswamy Sathyanarayanan <[email protected]>

PCI_ERS_RESULT_NEED_RESET error status implies the device is
requesting a slot reset and a notification about slot reset
completion via ->slot_reset() callback.

But in non-fatal errors case, if report_error_detected() or
report_mmio_enabled() functions requests PCI_ERS_RESULT_NEED_RESET
then current pcie_do_recovery() implementation does not do the
requested explicit slot reset, instead just calls the ->slot_reset()
callback on all affected devices. Notifying about the slot reset
completion without resetting it incorrect. So add this support.

Signed-off-by: Kuppuswamy Sathyanarayanan <[email protected]>
---
drivers/pci/pcie/err.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
index 5fe8561c7185..94d1c2ff7b40 100644
--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c
@@ -206,6 +206,9 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
* functions to reset slot before calling
* drivers' slot_reset callbacks?
*/
+ if (state != pci_channel_io_frozen)
+ pci_reset_bus(dev);
+
status = PCI_ERS_RESULT_RECOVERED;
pci_dbg(dev, "broadcast slot_reset message\n");
pci_walk_bus(bus, report_slot_reset, &status);
--
2.17.1


2020-06-28 13:00:35

by Yicong Yang

[permalink] [raw]
Subject: Re: [PATCH v2 2/2] PCI/ERR: Add reset support for non fatal errors

Hi Sathy,

one minor comments below.

On 2020/6/5 5:50, [email protected] wrote:
> From: Kuppuswamy Sathyanarayanan <[email protected]>
>
> PCI_ERS_RESULT_NEED_RESET error status implies the device is
> requesting a slot reset and a notification about slot reset
> completion via ->slot_reset() callback.
>
> But in non-fatal errors case, if report_error_detected() or
> report_mmio_enabled() functions requests PCI_ERS_RESULT_NEED_RESET
> then current pcie_do_recovery() implementation does not do the
> requested explicit slot reset, instead just calls the ->slot_reset()
> callback on all affected devices. Notifying about the slot reset
> completion without resetting it incorrect. So add this support.
>
> Signed-off-by: Kuppuswamy Sathyanarayanan <[email protected]>
> ---
> drivers/pci/pcie/err.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
> index 5fe8561c7185..94d1c2ff7b40 100644
> --- a/drivers/pci/pcie/err.c
> +++ b/drivers/pci/pcie/err.c
> @@ -206,6 +206,9 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
> * functions to reset slot before calling
> * drivers' slot_reset callbacks?
> */
> + if (state != pci_channel_io_frozen)
> + pci_reset_bus(dev);
> +

If it's the implementation to reset the slot, should we remove the TODO comments?
JYI.

Thanks,
Yicong


> status = PCI_ERS_RESULT_RECOVERED;
> pci_dbg(dev, "broadcast slot_reset message\n");
> pci_walk_bus(bus, report_slot_reset, &status);