Re: [PATCH 4/5] arm: dts: k3-j721e-beagleboneai64: Fix USB operation

[Roger Quadros <rogerq@kernel.org>]

On 20/01/2024 18:50, Tom Rini wrote:
> On Mon, Jan 15, 2024 at 01:40:00PM +0200, Roger Quadros wrote:
>>
>>
>> On 12/01/2024 15:21, Tom Rini wrote:
>>> On Fri, Jan 12, 2024 at 07:14:50AM -0600, Nishanth Menon wrote:
>>>> On 15:06-20240112, Roger Quadros wrote:
>>>>>
>>>>>
>>>>> On 12/01/2024 15:02, Nishanth Menon wrote:
>>>>>> On 14:49-20240112, Roger Quadros wrote:
>>>>>>> Without correct SERDES MUX and Lane control settings
>>>>>>> USB0 will be broken. Set the MUX and Lane control devices
>>>>>>> to be auto probed so they are configured correctly.
>>>>>>>
>>>>>>> Signed-off-by: Roger Quadros <rogerq@kernel.org>
>>>>>>> ---
>>>>>>>  arch/arm/dts/k3-j721e-beagleboneai64-u-boot.dtsi | 2 ++
>>>>>>>  1 file changed, 2 insertions(+)
>>>>>>>
>>>>>>> diff --git a/arch/arm/dts/k3-j721e-beagleboneai64-u-boot.dtsi b/arch/arm/dts/k3-j721e-beagleboneai64-u-boot.dtsi
>>>>>>> index f83caf7998..017a5a722e 100644
>>>>>>> --- a/arch/arm/dts/k3-j721e-beagleboneai64-u-boot.dtsi
>>>>>>> +++ b/arch/arm/dts/k3-j721e-beagleboneai64-u-boot.dtsi
>>>>>>> @@ -165,6 +165,7 @@
>>>>>>>  
>>>>>>>  &serdes_ln_ctrl {
>>>>>>>  	bootph-all;
>>>>>>> +	u-boot,mux-autoprobe;
>>>>>>>  };
>>>>>>>  
>>>>>>>  &serdes2_usb_link {
>>>>>>> @@ -173,6 +174,7 @@
>>>>>>>  
>>>>>>>  &usb_serdes_mux {
>>>>>>>  	bootph-all;
>>>>>>> +	u-boot,mux-autoprobe;
>>>>>>>  };
>>>>>>>  
>>>>>>>  &serdes_wiz2 {
>>>
>>> OK, so both of these are compatible = "mmio-mux", is the problem they
>>> aren't probed in time or something else?
>>>
>>
>> That's correct. They aren't probed ever. But that is because there are no
>> explicit consumers for them. Since this is a platform wide configuration,
>> we have been relying on the "idle-states" property and that they are auto-probed.
> 
> OK.  Could we borrow the "wrap" logic that drivers/led/led_gpio.c for
> example does to get the probe to happen inside drivers/mux/mmio.c
> instead? I feel like there might have been assumptions about grander
> needs back when the framework for muxers was done that has not panned
> out since.
> 

We only need the MUX driver to probe if the MUX node contains the "idle-states"
property.

So maybe the MUX UCLASS code should be checking for that instead of/along with
the custom u-boot,mux-autoprobe property?

How does this look?

diff --git a/drivers/mux/mux-uclass.c b/drivers/mux/mux-uclass.c
index c98576ceb8..8833888ded 100644
--- a/drivers/mux/mux-uclass.c
+++ b/drivers/mux/mux-uclass.c
@@ -318,7 +318,8 @@ int dm_mux_init(void)
 		return ret;
 	}
 	uclass_foreach_dev(dev, uc) {
-		if (dev_read_bool(dev, "u-boot,mux-autoprobe")) {
+		if (dev_read_bool(dev, "u-boot,mux-autoprobe") ||
+		    dev_read_bool(dev, "idle-states")) {
 			ret = device_probe(dev);
 			if (ret)
 				log_debug("unable to probe device %s\n",

-- 
cheers,
-roger