From: Wesley Sheng <wesley.sheng@microchip.com>
Date: Mon, 15 Apr 2019 22:41:42 +0800
Subject: switchtec: Fix unintended mask of MRPC event
Git-commit: 083c1b5e50b701899dc32445efa8b153685260d5
Patch-mainline: v5.2-rc1
References: git-fixes

When running application tool switchtec-user's `firmware update` and `event
wait` commands concurrently, sometimes the firmware update speed reduced
significantly.

It is because when the MRPC event happened after MRPC event occurrence
check but before the event mask loop reaches its header register in event
ISR, the MRPC event would be masked unintentionally.  Since there's no
chance to enable it again except for a module reload, all the following
MRPC execution completion checks time out.

Fix this bug by skipping the mask operation for MRPC event in event ISR,
same as what we already do for LINK event.

[js] 4.12 does not have the LINK event yet.

Fixes: 52eabba5bcdb ("switchtec: Add IOCTLs to the Switchtec driver")
Signed-off-by: Wesley Sheng <wesley.sheng@microchip.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/pci/switch/switchtec.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/pci/switch/switchtec.c
+++ b/drivers/pci/switch/switchtec.c
@@ -1314,6 +1314,9 @@ static int mask_event(struct switchtec_d
 	if (!(hdr & SWITCHTEC_EVENT_OCCURRED && hdr & SWITCHTEC_EVENT_EN_IRQ))
 		return 0;
 
+	if (eid == SWITCHTEC_IOCTL_EVENT_MRPC_COMP)
+ 		return 0;
+
 	dev_dbg(&stdev->dev, "%s: %d %d %x\n", __func__, eid, idx, hdr);
 	hdr &= ~(SWITCHTEC_EVENT_EN_IRQ | SWITCHTEC_EVENT_OCCURRED);
 	iowrite32(hdr, hdr_reg);