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FAILED: patch "[PATCH] cxl: Route eeh events to all drivers in" failed to apply to 4.4-stable tree

PATCH [email protected] 1 participant 1 message May 22, 2017

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The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

Quoted 1 line

From 4f58f0bf155e87dda31a3088b1e107fa9dd79f0e Mon Sep 17 00:00:00 2001

From: Vaibhav Jain <[email protected]>
Date: Thu, 27 Apr 2017 10:58:22 +0530
Subject: [PATCH] cxl: Route eeh events to all drivers in
cxl_pci_error_detected()

Fix a boundary condition where in some cases an eeh event that results in card reset isn't passed on to a driver attached to the virtual PCI device associated with a slice. This will happen in case when a slice attached device driver returns a value other than PCI_ERS_RESULT_NEED_RESET from the eeh error_detected() callback. This would result in an early return from cxl_pci_error_detected() and other drivers attached to other AFUs on the card wont be notified.

The patch fixes this by making sure that all slice attached device-drivers are notified and the return values from error_detected() callback are aggregated in a scheme where request for 'disconnect' trumps all and 'none' trumps 'need_reset'.

Fixes 9e8df8a21963 ("cxl: EEH support")
Cc [email protected] # v4.3+
Signed-off-by Vaibhav Jain <[email protected]>
Reviewed-by Andrew Donnellan <[email protected]>
Acked-by Frederic Barrat <[email protected]>
Signed-off-by Michael Ellerman <[email protected]>
drivers/misc/cxl/pci.c +9 -6
index 556ef910a651..c8e9e43c75a7 100644
@@ -2057,7 +2057,7 @@ static pci_ers_result_t cxl_pci_error_detected(struct pci_dev *pdev,
 {
 	struct cxl *adapter = pci_get_drvdata(pdev);
 	struct cxl_afu *afu;
-	pci_ers_result_t result = PCI_ERS_RESULT_NEED_RESET;
+	pci_ers_result_t result = PCI_ERS_RESULT_NEED_RESET, afu_result;
 	int i;
 
 	/* At this point, we could still have an interrupt pending.

@@ -2162,15 +2162,18 @@ static pci_ers_result_t cxl_pci_error_detected(struct pci_dev *pdev,
 	for (i = 0; i < adapter->slices; i++) {
 		afu = adapter->afu[i];
 
-		result = cxl_vphb_error_detected(afu, state);
-
-		/* Only continue if everyone agrees on NEED_RESET */
-		if (result != PCI_ERS_RESULT_NEED_RESET)
-			return result;
+		afu_result = cxl_vphb_error_detected(afu, state);
 
 		cxl_context_detach_all(afu);
 		cxl_ops->afu_deactivate_mode(afu, afu->current_mode);
 		pci_deconfigure_afu(afu);
+
+		/* Disconnect trumps all, NONE trumps NEED_RESET */
+		if (afu_result == PCI_ERS_RESULT_DISCONNECT)
+			result = PCI_ERS_RESULT_DISCONNECT;
+		else if ((afu_result == PCI_ERS_RESULT_NONE) &&
+			 (result == PCI_ERS_RESULT_NEED_RESET))
+			result = PCI_ERS_RESULT_NONE;
 	}
 
 	/* should take the context lock here */