From mboxrd@z Thu Jan 1 00:00:00 1970 From: rmk+kernel@arm.linux.org.uk (Russell King) Date: Wed, 23 Sep 2015 18:17:26 +0100 Subject: [PATCH 1/6] pci: mvebu: provide a compliant PCI configuration space In-Reply-To: <20150923171706.GL21084@n2100.arm.linux.org.uk> References: <20150923171706.GL21084@n2100.arm.linux.org.uk> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org PCI requires reads to reserved or unimplemented configuration space to return zero and complete normally. However, the root port software implementation was returning 0xfffffff and PCIBIOS_BAD_REGISTER_NUMBER. Fix this. Signed-off-by: Russell King --- drivers/pci/host/pci-mvebu.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c index 67ec5e1c99db..b6a096bc9422 100644 --- a/drivers/pci/host/pci-mvebu.c +++ b/drivers/pci/host/pci-mvebu.c @@ -515,8 +515,13 @@ static int mvebu_sw_pci_bridge_read(struct mvebu_pcie_port *port, break; default: - *value = 0xffffffff; - return PCIBIOS_BAD_REGISTER_NUMBER; + /* + * PCI defines configuration read accesses to reserved or + * unimplemented registers to read as zero and complete + * normally. + */ + *value = 0; + return PCIBIOS_SUCCESSFUL; } if (size == 2) -- 2.1.0