pci: pci_mvebu: Fix read_config() with PCI_SIZE_8 or PCI_SIZE_16

When reading 8 or 16 bits from config space, use appropriate readb() or
readw() calls. This ensures that PCIe controller does not read more bits
from endpoint card as asked by read_config() function.

Technically there should not be an issue with reading data from config
space which are not later used as there are no clear-by-read registers.
But it is better to use correct read operation based on requested size.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Stefan Roese <sr@denx.de>

diff --git a/drivers/pci/pci_mvebu.c b/drivers/pci/pci_mvebu.c
index 8175511..3991086 100644 (file)
--- a/drivers/pci/pci_mvebu.c
+++ b/drivers/pci/pci_mvebu.c
@@ -184,9 +184,22 @@ static int mvebu_pcie_read_config(const struct udevice *bus, pci_dev_t bdf,
        writel(PCIE_CONF_ADDR(bdf, offset), pcie->base + PCIE_CONF_ADDR_OFF);
 
        /* read data */
-       data = readl(pcie->base + PCIE_CONF_DATA_OFF);
+       switch (size) {
+       case PCI_SIZE_8:
+               data = readb(pcie->base + PCIE_CONF_DATA_OFF + (offset & 3));
+               break;
+       case PCI_SIZE_16:
+               data = readw(pcie->base + PCIE_CONF_DATA_OFF + (offset & 2));
+               break;
+       case PCI_SIZE_32:
+               data = readl(pcie->base + PCIE_CONF_DATA_OFF);
+               break;
+       default:
+               return -EINVAL;
+       }
+
        debug("(addr,size,val)=(0x%04x, %d, 0x%08x)\n", offset, size, data);
-       *valuep = pci_conv_32_to_size(data, offset, size);
+       *valuep = data;
 
        return 0;
 }