diff mbox series

[v4,12/31] pci: Adjust dm_pci_read_bar32() to return errors correctly

Message ID 20200407210023.v4.12.I36321d5e30daf051900f01f6289dfc58439871ea@changeid
State Superseded
Headers show
Series dm: Add programmatic generation of ACPI tables (part A) | expand

Commit Message

Simon Glass April 8, 2020, 3 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 at chromium.org>
Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner at br-automation.com>
---

Changes in v4: None
Changes in v3: None
Changes in v2: None

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

Patch

diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c
index ceb64517047..d2e10d6868a 100644
--- a/drivers/pci/pci-uclass.c
+++ b/drivers/pci/pci-uclass.c
@@ -1213,7 +1213,14 @@  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;