Re: [PATCH 2/3 v3] usb: chipidea: Fix Internal error: : 808 [#1] ARM related to STS flag

[Chris Ruehl <chris.ruehl@gtsys.com.hk>]

On Monday, December 02, 2013 01:10 PM, Peter Chen wrote:
>
>>
>> If you have a look into the function hw_write() you will see that there
>> is no
>> effect if hw_write(...,sts) is called with sts=0/1, because the mask will
>> cut
>> off all bits beside BIT(29).
>
> Yes, it is my careless. I thought sts is PORTCS_STS.
>
>> I used BIT(29) rather then PORTCS_STS to make it more clear what going on.
>
> It is not a good coding style, you do need use MACRO to instead of raw number directly.
>
>> A write to PORTCS will always be "0" for the STS Register no matter if
>> sts is 1
>> or 0 within Patch v2. Patch v3 will take care of the registers bit
>> position and
>> set 1 or 0 to PORTCS_STS.
>>
>
> My suggestion like below:
>
> 	if (ci->hw_bank.lpm) {
>   		hw_write(ci, OP_DEVLC, DEVLC_PTS(7) | DEVLC_PTW, lpm);
> -		hw_write(ci, OP_DEVLC, DEVLC_STS, sts);
> +		if (sts)
> +			hw_write(ci, OP_DEVLC, DEVLC_STS, DEVLC_STS);
>   	} else {
>   		hw_write(ci, OP_PORTSC, PORTSC_PTS(7) | PORTSC_PTW, portsc);
> -		hw_write(ci, OP_PORTSC, PORTSC_STS, sts);
> +		if (sts)
> +			hw_write(ci, OP_PORTSC, PORTSC_STS, PORTSC_STS);
>   	}
>
>
> I think we just need to fix the original bug, and do not add any new fixes
> since we don't know which one is correct for every platform. My proposal is
> just set PORTSC_STS (DEVLC_STS is lpm) if it is serial PHY. For any other PHYS, just keep
> the reset value.
>
> Peter
>
>> I used the imx27 reference manual Capital 30.8.1.5.12 PORTSCx.
>>

I can follow your arguments, ACK.
I prepare a patch set with this solution if not other people have better
ideas.

Chris