Re: [PATCH] tty: serial: sc16is7xx: use threaded interrupts instead of homegrow

["Sean Nyekjær" <sean.nyekjaer@prevas.dk>]

On 2016-03-07 17:58, Josh Cartwright wrote:
> On Mon, Mar 07, 2016 at 05:41:14PM +0100, Sebastian Andrzej Siewior wrote:
>> On 02/26/2016 08:00 PM, Josh Cartwright wrote:
>>> On Fri, Feb 26, 2016 at 01:26:27PM -0500, Kuba Kicinski wrote:
>>>> On 26 February 2016 11:52:28 GMT-05:00, Josh Cartwright <joshc@ni.com> wrote:
>>> [..]
>>>>> Instead, the driver needs to implement it's own oneshot-like
>>>>> handling at the device-level: in the registered irq handler, capture
>>>>> triggered interrupt state, squelch/mask, and enqueue the
>>>>> kthread_work.  In the tail-end of the kthread_work, re-enable
>>>>> interrupts at the device level.
>>>> The problem there being IIRC that i2c doesn't provide async writes so
>>>> we can't mask from irq callback. The only option would be
>>>> disable_irq/enable_irq, right?
>>> Ah, yes, that is a problem.  If by disable_irq(), you mean
>>> disable_irq_nosync(), then yes, I think that'd work.
>> I got lost here. Where do we stand here now?
> I understood the comment from Kuba to mean that he would be implementing
> the disable_irq()/enable_irq() idea above to fix all the problems with
> this driver.
>
> Kuba- did I read that right?
>
> Sean- are you still stuck without this?
The oneshot fix, fixed it for me :-)

We have encountered another problem regarding flow control in this driver.
Flowcontrol simply gets deactivated right after it's activated :-(
My college will submit a patch, hopefully in a couple of days...

And the "sc16is7xx_get_mctrl() is invoked under the uart port spinlock" 
problem is still there but with RT patches it's hidden.

/Sean
>
> Thanks for the ping,
>    Josh