According to the R-Car Gen2/3 manual, the bit 0 of MACCTLR register should be written by 0. To avoid unexpected behaviors from this incorrect setting, this patch fixes it.
Fixes: b3327f7fae66 ("PCI: rcar: Try increasing PCIe link speed to 5 GT/s at boot") Cc: stable@vger.kernel.org # v4.9+ Signed-off-by: Yoshihiro Shimoda yoshihiro.shimoda.uh@renesas.com --- drivers/pci/controller/pcie-rcar.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/controller/pcie-rcar.c b/drivers/pci/controller/pcie-rcar.c index f6a669a..9eb9b25 100644 --- a/drivers/pci/controller/pcie-rcar.c +++ b/drivers/pci/controller/pcie-rcar.c @@ -93,6 +93,7 @@ #define LINK_SPEED_2_5GTS (1 << 16) #define LINK_SPEED_5_0GTS (2 << 16) #define MACCTLR 0x011058 +#define MACCTLR_RESERVED BIT(0) #define SPEED_CHANGE BIT(24) #define SCRAMBLE_DISABLE BIT(27) #define PMSR 0x01105c @@ -427,7 +428,8 @@ static void rcar_pcie_force_speedup(struct rcar_pcie *pcie) rcar_pci_write_reg(pcie, macsr, MACSR);
/* Start link speed change */ - rcar_rmw32(pcie, MACCTLR, SPEED_CHANGE, SPEED_CHANGE); + rcar_rmw32(pcie, MACCTLR, SPEED_CHANGE | MACCTLR_RESERVED, + SPEED_CHANGE);
while (timeout--) { macsr = rcar_pci_read_reg(pcie, MACSR);