From: Pali Rohár pali@kernel.org
[ Upstream commit 838ff44a398ff47fe9b924961d91aee325821220 ]
PME Status bit in Root Status Register (PCIE_RC_RTSTA_OFF) is read-only and can be cleared only by writing 0b to the Interrupt Cause RW0C register (PCIE_INT_CAUSE_OFF).
Link: https://lore.kernel.org/r/20211125124605.25915-15-pali@kernel.org Fixes: 1f08673eef12 ("PCI: mvebu: Convert to PCI emulated bridge config space") Signed-off-by: Pali Rohár pali@kernel.org Signed-off-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pci/controller/pci-mvebu.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/controller/pci-mvebu.c b/drivers/pci/controller/pci-mvebu.c index 6100608e6413e..b690768d5a413 100644 --- a/drivers/pci/controller/pci-mvebu.c +++ b/drivers/pci/controller/pci-mvebu.c @@ -51,6 +51,8 @@ PCIE_CONF_FUNC(PCI_FUNC(devfn)) | PCIE_CONF_REG(where) | \ PCIE_CONF_ADDR_EN) #define PCIE_CONF_DATA_OFF 0x18fc +#define PCIE_INT_CAUSE_OFF 0x1900 +#define PCIE_INT_PM_PME BIT(28) #define PCIE_MASK_OFF 0x1910 #define PCIE_MASK_ENABLE_INTS 0x0f000000 #define PCIE_CTRL_OFF 0x1a00 @@ -604,7 +606,14 @@ mvebu_pci_bridge_emul_pcie_conf_write(struct pci_bridge_emul *bridge, break;
case PCI_EXP_RTSTA: - mvebu_writel(port, new, PCIE_RC_RTSTA); + /* + * PME Status bit in Root Status Register (PCIE_RC_RTSTA) + * is read-only and can be cleared only by writing 0b to the + * Interrupt Cause RW0C register (PCIE_INT_CAUSE_OFF). So + * clear PME via Interrupt Cause. + */ + if (new & PCI_EXP_RTSTA_PME) + mvebu_writel(port, ~PCIE_INT_PM_PME, PCIE_INT_CAUSE_OFF); break; } }