diff mbox series

[010/108] pci: Adjust dm_pci_read_bar32() to return errors correctly

Message ID 20200126220508.10.I36321d5e30daf051900f01f6289dfc58439871ea@changeid
State RFC
Delegated to: Bin Meng
Headers show
Series RFC: dm: Add programatic generation of ACPI tables | expand

Commit Message

Simon Glass Jan. 27, 2020, 5:05 a.m. UTC 
At present if reading a BAR returns 0xffffffff (e.g. the device is not
present) then the value is masked and a different value is returned.
This makes it harder to detect the problem when debugging.

Update the function to avoid masking in this case.

Signed-off-by: Simon Glass <sjg@chromium.org>
---

 drivers/pci/pci-uclass.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

Comments

Bin Meng Feb. 8, 2020, 3:15 p.m. UTC | #1 
On Mon, Jan 27, 2020 at 1:08 PM Simon Glass <sjg@chromium.org> wrote:
>
> At present if reading a BAR returns 0xffffffff (e.g. the device is not
> present) then the value is masked and a different value is returned.
> This makes it harder to detect the problem when debugging.
>
> Update the function to avoid masking in this case.
>
> Signed-off-by: Simon Glass <sjg@chromium.org>
> ---
>
>  drivers/pci/pci-uclass.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
>

Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff mbox series

Patch

diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c
index f5f713fdf4..ed57ff9ebe 100644
--- a/drivers/pci/pci-uclass.c
+++ b/drivers/pci/pci-uclass.c
@@ -1210,7 +1210,14 @@  u32 dm_pci_read_bar32(const struct udevice *dev, int barnum)
 
 	bar = PCI_BASE_ADDRESS_0 + barnum * 4;
 	dm_pci_read_config32(dev, bar, &addr);
-	if (addr & PCI_BASE_ADDRESS_SPACE_IO)
+
+	/*
+	 * If we get an invalid address, return this so that comparisons with
+	 * FDT_ADDR_T_NONE work correctly
+	 */
+	if (addr == 0xffffffff)
+		return addr;
+	else if (addr & PCI_BASE_ADDRESS_SPACE_IO)
 		return addr & PCI_BASE_ADDRESS_IO_MASK;
 	else
 		return addr & PCI_BASE_ADDRESS_MEM_MASK;