4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jean-Jacques Hiblot <jjhiblot@xxxxxx> commit 87cb12910a2ab6ed41ae951ea4d9c1cc1120199a upstream. AHCI provides the register PORTS_IMPL to let the software know which port is supported. The register must be initialized by the bootloader. However in some cases u-boot doesn't properly initialize this value (if it is not compiled with SATA support for example or if the SATA initialization fails). The DTS entry "ports-implemented" can be used to override the value in PORTS_IMPL. Without this patch the SATA will not work in the following two cases: * if there has been a failure to initialize SATA in u-boot. * if ahci_platform module has been removed and re-inserted. The reason is that the content of PORTS_IMPL is lost after the module is removed. I suspect that it's because the controller is reset by the hwmod. Signed-off-by: Jean-Jacques Hiblot <jjhiblot@xxxxxx> Acked-by: Roger Quadros <rogerq@xxxxxx> [tony@xxxxxxxxxxx: updated comments with what goes wrong] Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/arm/boot/dts/dra7.dtsi | 1 + arch/arm/boot/dts/omap5.dtsi | 1 + 2 files changed, 2 insertions(+) --- a/arch/arm/boot/dts/dra7.dtsi +++ b/arch/arm/boot/dts/dra7.dtsi @@ -1376,6 +1376,7 @@ phy-names = "sata-phy"; clocks = <&sata_ref_clk>; ti,hwmods = "sata"; + ports-implemented = <0x1>; }; rtc: rtc@48838000 { --- a/arch/arm/boot/dts/omap5.dtsi +++ b/arch/arm/boot/dts/omap5.dtsi @@ -985,6 +985,7 @@ phy-names = "sata-phy"; clocks = <&sata_ref_clk>; ti,hwmods = "sata"; + ports-implemented = <0x1>; }; dss: dss@58000000 { -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html