Re: [PATCHv2 1/2] amba pl011: workaround for uart registers lockup

From: Greg KH
Date: Tue May 17 2011 - 14:54:07 EST

On Tue, May 17, 2011 at 11:23:56AM -0700, Greg KH wrote:
> On Tue, May 17, 2011 at 10:50:17AM +0530, Shreshtha Kumar SAHU wrote:
> > From: Shreshtha Kumar Sahu <shreshthakumar.sahu@xxxxxxxxxxxxxx>
> >
> > This workaround aims to break the deadlock situation
> > which raises during continuous transfer of data for long
> > duration over uart with hardware flow control. It is
> > observed that CTS interrupt cannot be cleared in uart
> > interrupt register (ICR). Hence further transfer over
> > uart gets blocked.
> >
> > It is seen that during such deadlock condition ICR
> > don't get cleared even on multiple write. This leads
> > pass_counter to decrease and finally reach zero. This
> > can be taken as trigger point to run this UART_BT_WA.
> >
> > Workaround backups the register configuration, does soft
> > reset of UART using BIT-0 of PRCC_K_SOFTRST_SET/CLEAR
> > registers and restores the registers.
> >
> > This patch also provides support for uart init and exit
> > function calls if present.
> Why? You don't use these callbacks in this driver, so why add them?

Ok, I see them in the 2/2 patch now, thanks.

Do you still want me to take this patch through the serial tree, or will
both be going through some ARM tree?

greg k-h
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