Messages in this thread | | | Date | Wed, 29 Oct 2014 11:01:31 -0700 | From | Stephen Boyd <> | Subject | Re: [PATCH] serial: msm: Add magic SysRq support in dmmode |
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On 10/29/2014 09:38 AM, Daniel Thompson wrote: > Currently the _dm RX handler detects breaks but does not pass any > characters to uart_handle_sysrq_char(). > > The _dm optimizations combined with the port's spin lock make if > difficult to pass all characters to the sysrq logic because we cannot > safely call uart_handle_sysrq_char() when the lock is held without > deadlock (the console handler also takes the lock). > > Rather than passing all characters via uart_handle_sysrq_char() this patch > only passes the last few characters in the FIFO. This should include all > characters typed as a slow (human) rate. This makes the problem much > simpler and allows us to move the handling of these characters outside > of the port lock. This makes magic SysRq work if there is a human at > the keyboard (or a short delay in a script). > > Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> > ---
I have a patch that I was going to send for this (Frank R. and I have been looking at it since a month or two ago). This patch doesn't look correct given that the SR register is not actually accurate and doesn't indicate that a break is there in the fifo. I'll Cc you on the patch, please test it.
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