Messages in this thread | | | Date | Tue, 5 May 2015 12:11:56 +0100 | From | Dave P Martin <> | Subject | Re: [PATCH] serial/amba-pl011: fix minor bugs for pio mode |
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Hi,
On Tue, May 05, 2015 at 04:00:25AM +0100, Leo Yan wrote: > When use pio mode, there have two issues can be observed: > > - In the commit 2240197 "serial/amba-pl011: Leave the TX IRQ alone when > the UART is not open", it will skip clearing the TX IRQ across > pl011_shutdown() and pl011_startup(); So at the next time after the > uart port has been opened, there have chance for the function > pl011_tx_chars() will not be executed if the TX IRQ will not be > triggered; finally the console cannot output anymore. > > This is caused by the uart FIFO still keep data rather than > the threshold. So revert this patch to make sure every time open the > uart port, it will force to call function pl011_tx_chars(). > > - Sometimes will output the duplicate chars. Function pl011_tx_char() > will firstly send char and check if FIFO is full, and if the FIFO is > full it will return false; Caller function will consider the char > has _NOT_ been send out and resend it again, finally will send the > duplicate chars. So change to check FIFO is full or not, if full then > return false, otherwise send out char and return true. > > Signed-off-by: Leo Yan <leo.yan@linaro.org>
[...]
Thanks for the fixes, but I already posted patches that probably fix the issues you are observing, And Greg took them into his tty-testing branch.
Can you give them a try instead of your patches?
Dave Martin (2): Revert "serial/amba-pl011: Leave the TX IRQ alone when the UART is not open" serial/amba-pl011: Refactor and simplify TX FIFO handling
from
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git tty-testing
It would be good to have some feedback on them.
Cheers ---Dave
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