linux-kernel - Re: [PATCH 09/16] tty: serial: 8250_dma: Add a TX trigger workaround for AM33xx

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 17 Sep 2014 08:20:41 -0400
From:	Peter Hurley <peter@...leysoftware.com>
To:	Sebastian Andrzej Siewior <bigeasy@...utronix.de>
CC:	Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
	linux-serial@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-omap@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	tony@...mide.com, balbi@...com, gregkh@...uxfoundation.org,
	Alan Cox <alan@...ux.intel.com>
Subject: Re: [PATCH 09/16] tty: serial: 8250_dma: Add a TX trigger workaround
 for AM33xx

On 09/16/2014 12:55 PM, Sebastian Andrzej Siewior wrote:
> On 09/15/2014 07:01 PM, Sebastian Andrzej Siewior wrote:
>> On 09/11/2014 04:35 PM, Peter Hurley wrote:
>>> I do need to find out if omap hardware sets UART_MSR_DCTS when auto CTS
>>> is on. Would you mind running the debug patch below with HW flow control on?
>>
>> I didn't forget about this. However I told minicom to use hardware flow
>> control (and I see the driver set the HW bit) but I haven't seen that
>> uart_handle_cts_change() has been invoked at all. I'm going to check
>> two other boards and report then.
> 
> No, I don't get into this at all function.

Ok, good to know. Thanks for testing that.

> So I connected my am335x-evm
> with beagle board xm because both of them have an old fashion UART
> connector (instead those uart-to-usb). Both configured with HW-Flow and
> I haven't seen the function invoked but I saw "port->icount.overrun"
> being incremented. This shouldn't happen. So I am a little puzzled here…

Yeah, that's weird. Do you have a break-out box to confirm that RTS/CTS are
being driven?

Regards,
Peter Hurley

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/