[Regression] powerpc/usb: fix issue of CPU halt when missing USB PHY clock

[Regression] powerpc/usb: fix issue of CPU halt when missing USB PHY clock

[Ben Collins]

Hello,

The patch that checks the CTRL_PHY_CLK_VALID bit is failing incorrectly on my system (P4080DS). If I revert it, my system goes back to working correctly, but as is, it fails and wont allow my USB to work properly.

I've tried adding a loop to poll this bit 10,000 times with a udelay(1) on each loop and it still fails, so it doesn't appear to be a timing issue.

Is this check valid for all systems?

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RE: [Regression] powerpc/usb: fix issue of CPU halt when missing USB PHY clock

[Liu Shengzhou-B36685]

> -----Original Message-----
> From: Ben Collins [mailto:benmcollins13@gmail.com]
> Sent: Tuesday, February 28, 2012 12:11 AM
> To: Liu Shengzhou-B36685
> Cc: linux-kernel@vger.kernel.org
> Subject: [Regression] powerpc/usb: fix issue of CPU halt when missing
> USB PHY clock
> 
> Hello,
> 
> The patch that checks the CTRL_PHY_CLK_VALID bit is failing incorrectly
> on my system (P4080DS). If I revert it, my system goes back to working
> correctly, but as is, it fails and wont allow my USB to work properly.
> 
> I've tried adding a loop to poll this bit 10,000 times with a udelay(1)
> on each loop and it still fails, so it doesn't appear to be a timing
> issue.
> 
> Is this check valid for all systems?
> 

This check is valid for P3060/P3041/P5020/P1023 platform.
on some platforms, there is this bit, but not on other some platforms.
For P4080, just revert this patch, then USB is able to work.
I'll post a new patch to fix it after getting some confirmations from silicon team.

Thanks,
Shengzhou