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SubjectRe: [PATCH 1/2] amba pl011: workaround for uart registers lockup
On Mon, May 16, 2011 at 06:31:18PM +0530, Shreshtha Kumar SAHU wrote:
> From: Shreshtha Kumar Sahu <>
> 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.
> Signed-off-by: Shreshtha Kumar Sahu <>

Please always run your patches through scripts/ so we don't
end up telling you to fix up the same obvious things that this tool
would tell you needs to be fixed...


greg k-h

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