Re: [PATCH v8 1/2] PCI/ERR: Call pci_bus_reset() before calling ->slot_reset() callback

From: Kuppuswamy, Sathyanarayanan
Date: Fri Nov 13 2020 - 16:59:01 EST


Hi Bjorn,

On 10/26/20 12:37 PM, Kuppuswamy Sathyanarayanan wrote:
Currently if report_error_detected() or report_mmio_enabled()
functions requests PCI_ERS_RESULT_NEED_RESET, current
pcie_do_recovery() implementation does not do the requested
explicit device reset, but instead just calls the
report_slot_reset() on all affected devices. Notifying about the
reset via report_slot_reset() without doing the actual device
reset is incorrect. So call pci_bus_reset() before triggering
->slot_reset() callback.
Any comments on this series?

Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
Reviewed-by: Sinan Kaya <okaya@xxxxxxxxxx>
Reviewed-by: Ashok Raj <ashok.raj@xxxxxxxxx>
---
Changes since v7:
* Rebased on top of v5.10-rc1.

Changes since v6:
* None.

Changes since v5:
* Added Ashok's Reviewed-by tag.

Changes since v4:
* Added check for pci_reset_bus() return value.

drivers/pci/pcie/err.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
index c543f419d8f9..315a4d559c4c 100644
--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c
@@ -152,6 +152,7 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
{
pci_ers_result_t status = PCI_ERS_RESULT_CAN_RECOVER;
struct pci_bus *bus;
+ int ret;
/*
* Error recovery runs on all subordinates of the first downstream port.
@@ -181,11 +182,12 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
}
if (status == PCI_ERS_RESULT_NEED_RESET) {
- /*
- * TODO: Should call platform-specific
- * functions to reset slot before calling
- * drivers' slot_reset callbacks?
- */
+ ret = pci_reset_bus(dev);
+ if (ret < 0) {
+ pci_err(dev, "Failed to reset %d\n", ret);
+ status = PCI_ERS_RESULT_DISCONNECT;
+ goto failed;
+ }
status = PCI_ERS_RESULT_RECOVERED;
pci_dbg(dev, "broadcast slot_reset message\n");
pci_walk_bus(bus, report_slot_reset, &status);


--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer