PCI/ERR: Update device error_state already after reset

After a Fatal Error has been reported by a device and has been recovered
through a Secondary Bus Reset, AER updates the device's error_state to
pci_channel_io_normal before invoking its driver's ->resume() callback.

By contrast, EEH updates the error_state earlier, namely after resetting
the device and before invoking its driver's ->slot_reset() callback.
Commit c58dc57 ("powerpc/pseries: Set error_state to
pci_channel_io_normal in eeh_report_reset()") explains in great detail
that the earlier invocation is necessitated by various drivers checking
accessibility of the device with pci_channel_offline() and avoiding
accesses if it returns true.  It returns true for any other error_state
than pci_channel_io_normal.

The device should be accessible already after reset, hence the reasoning
is that it's safe to update the error_state immediately afterwards.

This deviation between AER and EEH seems problematic because drivers
behave differently depending on which error recovery mechanism the
platform uses.  Three drivers have gone so far as to update the
error_state themselves, presumably to work around AER's behavior.

For consistency, amend AER to update the error_state at the same recovery
steps as EEH.  Drop the now unnecessary workaround from the three drivers.

Keep updating the error_state before ->resume() in case ->error_detected()
or ->mmio_enabled() return PCI_ERS_RESULT_RECOVERED, which causes
->slot_reset() to be skipped.  There are drivers doing this even for Fatal
Errors, e.g. mhi_pci_error_detected().

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/4517af6359ffb9d66152b827a5d2833459144e3f.1755008151.git.lukas@wunner.de

Author: l1k

drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_hw.c

@@ -4215,7 +4215,6 @@ static pci_ers_result_t qlcnic_83xx_io_slot_reset(struct pci_dev *pdev)
 	struct qlcnic_adapter *adapter = pci_get_drvdata(pdev);
 	int err = 0;
 
-	pdev->error_state = pci_channel_io_normal;
 	err = pci_enable_device(pdev);
 	if (err)
 		goto disconnect;

drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c

@@ -3766,8 +3766,6 @@ static int qlcnic_attach_func(struct pci_dev *pdev)
 	struct qlcnic_adapter *adapter = pci_get_drvdata(pdev);
 	struct net_device *netdev = adapter->netdev;
 
-	pdev->error_state = pci_channel_io_normal;
-
 	err = pci_enable_device(pdev);
 	if (err)
 		return err;

drivers/pci/pcie/err.c

@@ -153,7 +153,8 @@ static int report_slot_reset(struct pci_dev *dev, void *data)
 
 	device_lock(&dev->dev);
 	pdrv = dev->driver;
-	if (!pdrv || !pdrv->err_handler || !pdrv->err_handler->slot_reset)
+	if (!pci_dev_set_io_state(dev, pci_channel_io_normal) ||
+	    !pdrv || !pdrv->err_handler || !pdrv->err_handler->slot_reset)
 		goto out;
 
 	err_handler = pdrv->err_handler;

drivers/scsi/qla2xxx/qla_os.c

@@ -7883,11 +7883,6 @@ qla2xxx_pci_slot_reset(struct pci_dev *pdev)
 	       "Slot Reset.\n");
 
 	ha->pci_error_state = QLA_PCI_SLOT_RESET;
-	/* Workaround: qla2xxx driver which access hardware earlier
-	 * needs error state to be pci_channel_io_online.
-	 * Otherwise mailbox command timesout.
-	 */
-	pdev->error_state = pci_channel_io_normal;
 
 	pci_restore_state(pdev);