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From: Corey Minyard <minyard@acm.org>
To: Craig Shelley <craig@microtron.org.uk>, Johan Hovold <johan@kernel.org>
Cc: Linux Kernel <linux-kernel@vger.kernel.org>, linux-usb@vger.kernel.org
Subject: Break doesn't work on a CP2105
Date: Wed, 26 Apr 2023 15:04:03 -0500	[thread overview]
Message-ID: <ZEmDs0ASdnEAnpsL@minyard.net> (raw)

I have a development board with a CP2105 on it, and I was trying to send
a break to it to do a sysrq.  And it wasn't working.

I have verified that the target driver works by setting a really slow
baud rate and sending something with a lot of zero bits.  It got breaks
just fine.

If I use TCSBRK, it seems to just send a short time with zeros, not
even a full character's worth.  It receives a valid character with the
top few bits set.  If I use TCSBRKP with a longer time, like 2.5
seconds, it waits the whole time, then at the very end it gets the
character as with the shorter break.

I can't find a programming manual for the chip, and I'm not sure what's
going on.

-corey

             reply	other threads:[~2023-04-26 20:04 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-26 20:04 Corey Minyard [this message]
2023-04-26 23:42 ` [PATCH] USB: serial: cp210x: work around silicon bug setting break minyard
2023-05-22 11:59 ` Break doesn't work on a CP2105 Johan Hovold
2023-05-22 12:52   ` Corey Minyard
2023-06-02 12:53     ` Johan Hovold
2023-06-02 16:46       ` Corey Minyard
2023-06-04 12:17         ` Johan Hovold
2023-06-04 20:11           ` Corey Minyard
2023-06-05  7:15             ` Johan Hovold
2023-06-05 12:25               ` Corey Minyard

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