[PATCH 5.4 02/50] PCI: aardvark: Indicate error in val when config read fails

[Greg Kroah-Hartman]

From: Pali Rohár <pali@xxxxxxxxxx>

commit b1bd5714472cc72e14409f5659b154c765a76c65 upstream.

Most callers of config read do not check for return value. But most of the
ones that do, checks for error indication in 'val' variable.

This patch updates error handling in advk_pcie_rd_conf() function. If PIO
transfer fails then 'val' variable is set to 0xffffffff which indicates
failture.

Link: https://lore.kernel.org/r/20200528162604.GA323482@bjorn-Precision-5520
Link: https://lore.kernel.org/r/20200601130315.18895-1-pali@xxxxxxxxxx
Reported-by: Bjorn Helgaas <helgaas@xxxxxxxxxx>
Signed-off-by: Pali Rohár <pali@xxxxxxxxxx>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/pci/controller/pci-aardvark.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -664,8 +664,10 @@ static int advk_pcie_rd_conf(struct pci_
 	advk_writel(pcie, 1, PIO_START);
 
 	ret = advk_pcie_wait_pio(pcie);
-	if (ret < 0)
+	if (ret < 0) {
+		*val = 0xffffffff;
 		return PCIBIOS_SET_FAILED;
+	}
 
 	/* Check PIO status and get the read result */
 	ret = advk_pcie_check_pio_status(pcie, val);