arm: a37xx: pci: Disable returning CRS response

There was mistake in commit 4cd61c43fd51 ("arm: a37xx: pci: Fix handling
PIO config error responses"). U-Boot does not support handling of CRS
return value for PCI_VENDOR_ID config read request and also does not set
CRSSVE bit.

Therefore disable returning CRS response for now.

Signed-off-by: Pali Rohár <pali@kernel.org>
Fixes: 4cd61c43fd51 ("arm: a37xx: pci: Fix handling PIO config error responses")
Reviewed-by: Stefan Roese <sr@denx.de>

diff --git a/drivers/pci/pci-aardvark.c b/drivers/pci/pci-aardvark.c
index 815b261..d3ef8f2 100644 (file)
--- a/drivers/pci/pci-aardvark.c
+++ b/drivers/pci/pci-aardvark.c
@@ -358,7 +358,18 @@ static int pcie_advk_read_config(const struct udevice *bus, pci_dev_t bdf,
                return 0;
        }
 
-       allow_crs = (offset == PCI_VENDOR_ID) && (size == 4);
+       /*
+        * Returning fabricated CRS value (0xFFFF0001) by PCIe Root Complex to
+        * OS is allowed only for 4-byte PCI_VENDOR_ID config read request and
+        * only when CRSSVE bit in Root Port PCIe device is enabled. In all
+        * other error PCIe Root Complex must return all-ones.
+        * Aardvark HW does not have Root Port PCIe device and U-Boot does not
+        * implement emulation of this device.
+        * U-Boot currently does not support handling of CRS return value for
+        * PCI_VENDOR_ID config read request and also does not set CRSSVE bit.
+        * Therefore disable returning CRS response for now.
+        */
+       allow_crs = false;
 
        if (advk_readl(pcie, PIO_START)) {
                dev_err(pcie->dev,