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: stable@vger.kernel.org # v5.2+ Signed-off-by: Yoshihiro Shimoda yoshihiro.shimoda.uh@renesas.com Reviewed-by: Sergei Shtylyov sergei.shtylyov@cogentembedded.com Reviewed-by: Geert Uytterhoeven geert+renesas@glider.be --- 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); }