According to the R-Car Gen2/3 manual, "Be sure to write the initial value (= H'80FF 0000) to MACCTLR before enabling PCIETCTLR.CFINIT". To avoid unexpected behaviors, this patch fixes it. Note that the SPCHG bit of MACCTLR register description said "Only writing 1 is valid and writing 0 is invalid" but this "invalid" means "ignored", not "prohibited". So, any documentation conflict doesn't exist about writing the MACCTLR register.
Reported-by: Eugeniu Rosca erosca@de.adit-jv.com Fixes: c25da4778803 ("PCI: rcar: Add Renesas R-Car PCIe driver") Fixes: be20bbcb0a8c ("PCI: rcar: Add the initialization of PCIe link in resume_noirq()") Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Yoshihiro Shimoda yoshihiro.shimoda.uh@renesas.com Reviewed-by: Geert Uytterhoeven geert+renesas@glider.be --- drivers/pci/controller/pcie-rcar.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/pci/controller/pcie-rcar.c b/drivers/pci/controller/pcie-rcar.c index 40d8c54..94ba4fe 100644 --- a/drivers/pci/controller/pcie-rcar.c +++ b/drivers/pci/controller/pcie-rcar.c @@ -91,8 +91,11 @@ #define LINK_SPEED_2_5GTS (1 << 16) #define LINK_SPEED_5_0GTS (2 << 16) #define MACCTLR 0x011058 +#define MACCTLR_NFTS_MASK GENMASK(23, 16) /* The name is from SH7786 */ #define SPEED_CHANGE BIT(24) #define SCRAMBLE_DISABLE BIT(27) +#define LTSMDIS BIT(31) +#define MACCTLR_INIT_VAL (LTSMDIS | MACCTLR_NFTS_MASK) #define PMSR 0x01105c #define MACS2R 0x011078 #define MACCGSPSETR 0x011084 @@ -613,6 +616,8 @@ static int rcar_pcie_hw_init(struct rcar_pcie *pcie) if (IS_ENABLED(CONFIG_PCI_MSI)) rcar_pci_write_reg(pcie, 0x801f0000, PCIEMSITXR);
+ rcar_pci_write_reg(pcie, MACCTLR_INIT_VAL, MACCTLR); + /* Finish initialization - establish a PCI Express link */ rcar_pci_write_reg(pcie, CFINIT, PCIETCTLR);
@@ -1235,6 +1240,7 @@ static int rcar_pcie_resume_noirq(struct device *dev) return 0;
/* Re-establish the PCIe link */ + rcar_pci_write_reg(pcie, MACCTLR_INIT_VAL, MACCTLR); rcar_pci_write_reg(pcie, CFINIT, PCIETCTLR); return rcar_pcie_wait_for_dl(pcie); }