Thread (27 messages) 27 messages, 3 authors, 2015-12-05

[PATCH LINUX v3 09/10] tty: xuartps: Only handle RX IRQs when RX is enabled

From: Sören Brinkmann <hidden>
Date: 2015-12-05 22:19:28
Also in: linux-serial, lkml

On Sat, 2015-12-05 at 12:43PM -0500, Peter Hurley wrote:
On 11/21/2015 09:59 PM, Soren Brinkmann wrote:
quoted
Ignore RX-related interrupts if RX is not enabled.
This doesn't look like a safe approach; fast-forward a couple of years and
some is trying to add some feature but can't figure out why no data is
arriving...

What is this trying to solve?
I definitely saw two kinds of lock ups. One was on the TX side, that the
system tried to print with the transmitter disabled.

The other on the RX side. I don't recall the details, but the system was
stuck in some RX-related function waiting for data while the receiver
was disabled. I think my explanation was that some IRQ condition becomes
true and is dispatched to the RX handler even though the receiver isn't
enabled.
I guess a better way for solving this would be to disable the IRQs that
call the RX handler when the receiver is disabled.

	S?ren
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