According to the R-Car Gen2/3 manual, the bit 0 of MACCTLR register
should be written to 0 before enabling PCIETCTLR.CFINIT because
the bit 0 is set to 1 on reset. To avoid unexpected behaviors from
this incorrect setting, this patch fixes it.
Fixes: c25da4778803 ("PCI: rcar: Add Renesas R-Car PCIe driver")
Fixes: be20bbcb0a8c ("PCI: rcar: Add the initialization of PCIe link in
resume_noirq()")
Cc: <[email protected]> # v5.2+
Signed-off-by: Yoshihiro Shimoda <[email protected]>
Reviewed-by: Sergei Shtylyov <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
---
Changes from v3:
- Add the setting in rcar_pcie_resume_noirq().
- Add Fixes tag for rcar_pcie_resume_noirq().
- Change the version of the stable ML from v3.16 to v5.2.
https://patchwork.kernel.org/patch/11181005/
Changes from v2:
- Change the subject.
- Fix commit log again.
- Add the register setting into the initialization, instead of speedup.
- Change commit hash/target version on Fixes and Cc stable tags.
- Add Geert-san's Reviewed-by.
https://patchwork.kernel.org/patch/11180429/
Changes from v1:
- Fix commit log.
- Add Sergei-san's Reviewed-by.
https://patchwork.kernel.org/patch/11179279/
drivers/pci/controller/pcie-rcar.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/pci/controller/pcie-rcar.c
b/drivers/pci/controller/pcie-rcar.c
index f6a669a..302c9ea 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
@@ -615,6 +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_rmw32(pcie, MACCTLR, MACCTLR_RESERVED, 0);
+
/* Finish initialization - establish a PCI Express link */
rcar_pci_write_reg(pcie, CFINIT, PCIETCTLR);
@@ -1237,6 +1240,7 @@ static int rcar_pcie_resume_noirq(struct device *dev)
return 0;
/* Re-establish the PCIe link */
+ rcar_rmw32(pcie, MACCTLR, MACCTLR_RESERVED, 0);
rcar_pci_write_reg(pcie, CFINIT, PCIETCTLR);
return rcar_pcie_wait_for_dl(pcie);
}
--
2.7.4
