From f58d5f53c89479c12ad719c1960176442add5aaa Mon Sep 17 00:00:00 2001
From: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Date: Wed, 26 Feb 2020 14:52:23 +0900
Subject: [PATCH] PCI: endpoint: Fix clearing start entry in configfs
Git-commit: f58d5f53c89479c12ad719c1960176442add5aaa
Patch-mainline: v5.7-rc1
References: bsc#1051510

After an endpoint is started through configfs, if 0 is written to the
configfs entry 'start', the controller stops but the epc_group->start
value remains 1.

A subsequent unlinking of the function from the controller would trigger
a spurious WARN_ON_ONCE() in pci_epc_epf_unlink() despite right
behavior.

Fix it by setting epc_group->start = 0 when a controller is stopped
using configfs.

Fixes: d74679911610 ("PCI: endpoint: Introduce configfs entry for configuring EP functions")
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/pci/endpoint/pci-ep-cfs.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/pci/endpoint/pci-ep-cfs.c b/drivers/pci/endpoint/pci-ep-cfs.c
index e7e8367eead1..55edce50be96 100644
--- a/drivers/pci/endpoint/pci-ep-cfs.c
+++ b/drivers/pci/endpoint/pci-ep-cfs.c
@@ -57,6 +57,7 @@ static ssize_t pci_epc_start_store(struct config_item *item, const char *page,
 
 	if (!start) {
 		pci_epc_stop(epc);
+		epc_group->start = 0;
 		return len;
 	}
 
-- 
2.16.4