Commit c003ca99 authored Oct 08, 2015 by Gabriele Paoloni Committed by Bjorn Helgaas Nov 02, 2015

PCI: designware: Use exact access size in dw_pcie_cfg_read()



dw_pcie_cfg_write() uses the exact 8-, 16-, or 32-bit access size
requested, but dw_pcie_cfg_read() previously performed a 32-bit read and
masked out the bits requested.

Use the exact access size in dw_pcie_cfg_read().  For example, if we want
an 8-bit read, use readb() instead of using readl() and masking out the 8
bits we need.  This makes it symmetric with dw_pcie_cfg_write().

[bhelgaas: split into separate patch, set *val = 0 in failure case]
Signed-off-by: Gabriele Paoloni <gabriele.paoloni@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

parent fa3b7cba

drivers/pci/host/pcie-designware.c

+8 −6

Original line number	Diff line number	Diff line
		@@ -82,14 +82,16 @@ static inline struct pcie_port sys_to_pcie(struct pci_sys_data sys)

		int dw_pcie_cfg_read(void __iomem addr, int where, int size, u32 val)
		{
		if (size == 4)
		*val = readl(addr);

		if (size == 1)
		val = (val >> (8 * (where & 3))) & 0xff;
		else if (size == 2)
		val = (val >> (8 * (where & 3))) & 0xffff;
		else if (size != 4)
		*val = readw(addr + (where & 2));
		else if (size == 1)
		*val = readb(addr + (where & 1));
		else {
		*val = 0;
		return PCIBIOS_BAD_REGISTER_NUMBER;
		}

		return PCIBIOS_SUCCESSFUL;
		}