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: Marek Behún <kabel@xxxxxxxxxx> 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 @@ -596,8 +596,10 @@ 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);