Am 18.02.2017 00:26, schrieb Dan Carpenter:
> The bug is that "val" is unsigned long but we only initialize 32 bits
> of it. Then we test "if (val)" and that might be true not because we
> set the bits but because some were never initialized.
>
> Fixes: f342d940ee0e ("PCI: exynos: Add support for MSI")
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> ---
> Static analysis. Not tested.
>
> diff --git a/drivers/pci/dwc/pcie-designware.c b/drivers/pci/dwc/pcie-designware.c
> index af8f6e92e885..5bfc377b83e4 100644
> --- a/drivers/pci/dwc/pcie-designware.c
> +++ b/drivers/pci/dwc/pcie-designware.c
> @@ -257,17 +257,18 @@ static struct irq_chip dw_msi_irq_chip = {
> /* MSI int handler */
> irqreturn_t dw_handle_msi_irq(struct pcie_port *pp)
> {
> - unsigned long val;
> + u32 val;
> int i, pos, irq;
> irqreturn_t ret = IRQ_NONE;
>
> for (i = 0; i < MAX_MSI_CTRLS; i++) {
> dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_STATUS + i * 12, 4,
> - (u32 *)&val);
> + &val);
> if (val) {
why not
if (!val) continue;
it would save an entire indent level and make things a bit more easy to read.
> ret = IRQ_HANDLED;
> pos = 0;
> - while ((pos = find_next_bit(&val, 32, pos)) != 32) {
> + while ((pos = find_next_bit((unsigned long *)&val, 32,
> + pos)) != 32) {
> irq = irq_find_mapping(pp->irq_domain,
> i * 32 + pos);
irq seems to be 0 when nothing is found. This can never happen ?
find_next_bit() feels a bit overpowered perhaps a simple loop
would be more effective and more easy to understand ?
something like:
while ( val) {
if (val & 1 )
found ...
val>>=1;
pos++;
}
just my 2 cents,
re,
wh
> dw_pcie_wr_own_conf(pp,
