[PATCH] PCI: endpoint: functions/pci-epf-test: Avoid DMA release when DMA is unsupported

[Kunihiko Hayashi]

When unbinding pci_epf_test, pci_epf_test_clean_dma_chan() is called in
pci_epf_test_unbind() even though epf_test->dma_supported is false.
As a result, dma_release_channel() will occur null pointer access because
dma_chan isn't set.

This avoids calling dma_release_channel() if epf_test->dma_supported
is false.

Fixes: a1d105d4ab8e ("PCI: endpoint: functions/pci-epf-test: Add DMA support to transfer data")
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx>
---
 drivers/pci/endpoint/functions/pci-epf-test.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
index 3b4cf7e..8b4f136 100644
--- a/drivers/pci/endpoint/functions/pci-epf-test.c
+++ b/drivers/pci/endpoint/functions/pci-epf-test.c
@@ -609,7 +609,8 @@ static void pci_epf_test_unbind(struct pci_epf *epf)
 	int bar;
 
 	cancel_delayed_work(&epf_test->cmd_handler);
-	pci_epf_test_clean_dma_chan(epf_test);
+	if (epf_test->dma_supported)
+		pci_epf_test_clean_dma_chan(epf_test);
 	pci_epc_stop(epc);
 	for (bar = 0; bar < PCI_STD_NUM_BARS; bar++) {
 		epf_bar = &epf->bar[bar];
-- 
2.7.4