Re: [PATCH v5] arm64: dts: ti: k3-j784s4-main: Fix mux-reg-masks in serdes_ln_ctrl

[Andrew Davis <afd@ti.com>]

On 2/13/24 3:19 AM, Peter Rosin wrote:
> Hi!
> 
> 2024-02-13 at 09:03, Siddharth Vadapalli wrote:
>> From: Chintan Vankar <c-vankar@ti.com>
>>
>> Change offset in mux-reg-masks property for serdes_ln_ctrl node
>> since reg-mux property is used in compatible.
>>
>> Fixes: 2765149273f4 ("mux: mmio: use reg property when parent device is not a syscon")
>> Signed-off-by: Chintan Vankar <c-vankar@ti.com>
>> Acked-by: Andrew Davis <afd@ti.com>
>> Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
>> ---
>> Hello,
>>
>> This patch is based on linux-next tagged next-20240213.
>> The v4 of this patch is a part of the series at:
>> https://lore.kernel.org/r/20240131101441.1362409-1-c-vankar@ti.com/
>>
>> Since the v4 series mentioned above has open comments on the other
>> patches in the series, this patch is being posted separately to unblock
>> other dependent series which rely on the fix implemented by this patch.
>>
>> Changes since v4:
>> - Rebased patch on linux-next tagged next-20240213.
>>
>> Regards,
>> Siddharth.
>>
>>   arch/arm64/boot/dts/ti/k3-j784s4-main.dtsi | 12 ++++++------
>>   1 file changed, 6 insertions(+), 6 deletions(-)
>>
>> diff --git a/arch/arm64/boot/dts/ti/k3-j784s4-main.dtsi b/arch/arm64/boot/dts/ti/k3-j784s4-main.dtsi
>> index 3cb964982792..3b7f0eca977b 100644
>> --- a/arch/arm64/boot/dts/ti/k3-j784s4-main.dtsi
>> +++ b/arch/arm64/boot/dts/ti/k3-j784s4-main.dtsi
>> @@ -52,12 +52,12 @@ serdes_ln_ctrl: mux-controller@4080 {
>>   			compatible = "reg-mux";
>>   			reg = <0x00004080 0x30>;
>>   			#mux-control-cells = <1>;
>> -			mux-reg-masks = <0x4080 0x3>, <0x4084 0x3>, /* SERDES0 lane0/1 select */
>> -					<0x4088 0x3>, <0x408c 0x3>, /* SERDES0 lane2/3 select */
>> -					<0x4090 0x3>, <0x4094 0x3>, /* SERDES1 lane0/1 select */
>> -					<0x4098 0x3>, <0x409c 0x3>, /* SERDES1 lane2/3 select */
>> -					<0x40a0 0x3>, <0x40a4 0x3>, /* SERDES2 lane0/1 select */
>> -					<0x40a8 0x3>, <0x40ac 0x3>; /* SERDES2 lane2/3 select */
>> +			mux-reg-masks = <0x0 0x3>, <0x4 0x3>, /* SERDES0 lane0/1 select */
>> +					<0x8 0x3>, <0xc 0x3>, /* SERDES0 lane2/3 select */
>> +					<0x10 0x3>, <0x14 0x3>, /* SERDES1 lane0/1 select */
>> +					<0x18 0x3>, <0x1c 0x3>, /* SERDES1 lane2/3 select */
>> +					<0x20 0x3>, <0x24 0x3>, /* SERDES2 lane0/1 select */
>> +					<0x28 0x3>, <0x2c 0x3>; /* SERDES2 lane2/3 select */
>>   			idle-states = <J784S4_SERDES0_LANE0_PCIE1_LANE0>,
>>   				      <J784S4_SERDES0_LANE1_PCIE1_LANE1>,
>>   				      <J784S4_SERDES0_LANE2_IP3_UNUSED>,
> 
> Ouch. I suspect there is a similar problem in
> arch/arm64/boot/dts/ti/k3-j721e-mcu-wakeup.dtsi:
> 
> 
> 	fss: bus@47000000 {
> 		compatible = "simple-bus";
> 		reg = <0x0 0x47000000 0x0 0x100>;
> 		#address-cells = <2>;
> 		#size-cells = <2>;
> 		ranges;
> 
> 		hbmc_mux: mux-controller@47000004 {
> 			compatible = "reg-mux";
> 			reg = <0x00 0x47000004 0x00 0x2>;
> 			#mux-control-cells = <1>;
> -			mux-reg-masks = <0x4 0x2>; /* HBMC select */
> +			mux-reg-masks = <0x0 0x2>; /* HBMC select */
> 		};
> 
> Who knows what non-upstreamed devices and devicetrees are affected?
> I guess we need to revert 2765149273f4 ("mux: mmio: use reg property
> when parent device is not a syscon") unless someone sees a sane way
> to fix this.

There are only two in-tree nodes with "reg-mux" with a reg property: the
one this patch fixes, and the hbmc_mux you point out, both in TI devices.
I'd say it is safe to assume we are the only users, and our non-upstreamed
DTs depend on that patch, reverting it would cause more issues for
out-of-tree users than just fixing the two broken nodes above.

Andrew

> 
> Cheers,
> Peter