From: Alan Mikhak <alan.mikhak@sifive.com>

commit db7a62482d2f6a63f36f30f62c4cbf1e53035719 upstream.

Set endpoint controller pointer to NULL in pci_epc_remove_epf()
to avoid -EBUSY on subsequent call to pci_epc_add_epf().

Add a check for NULL endpoint function pointer.

Signed-off-by: Alan Mikhak <alan.mikhak@sifive.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
 drivers/pci/endpoint/pci-epc-core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index e4712a0f249c..2091508c1620 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -519,11 +519,12 @@ void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf)
 {
 	unsigned long flags;
 
-	if (!epc || IS_ERR(epc))
+	if (!epc || IS_ERR(epc) || !epf)
 		return;
 
 	spin_lock_irqsave(&epc->lock, flags);
 	list_del(&epf->list);
+	epf->epc = NULL;
 	spin_unlock_irqrestore(&epc->lock, flags);
 }
 EXPORT_SYMBOL_GPL(pci_epc_remove_epf);
-- 
2.17.1