[PATCH v4 2/2] PCI: rcar: Fix missing MACCTLR register setting in initialize sequence

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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@xxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxx> # v5.2+
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
 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);
 }
-- 
2.7.4




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