From: Simon Glass <sjg@chromium.org>
Date: Thu, 9 Apr 2020 16:27:36 +0000 (-0600)
Subject: pci: Adjust dm_pci_read_bar32() to return errors correctly
X-Git-Url: http://git.dujemihanovic.xyz/?a=commitdiff_plain;h=9ece4b090fdda97177ac9b3470e9b7de839eb59d;p=u-boot.git

pci: Adjust dm_pci_read_bar32() to return errors correctly

At present if reading a BAR returns 0xffffffff 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>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---

diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c
index ceb6451704..d2e10d6868 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;