Re: [PATCH] serial: 8250: 8250_omap: Fix possible interrupt storm

From: Andy Shevchenko
Date: Tue Jul 13 2021 - 05:14:06 EST


On Tue, Jul 13, 2021 at 11:54 AM Vignesh Raghavendra <vigneshr@xxxxxx> wrote:
> On 7/13/21 1:57 AM, andy@surfacebook.localdomain wrote:
> > Tue, Jun 22, 2021 at 11:53:38AM +0530, Vignesh Raghavendra kirjoitti:

...

> > https://lore.kernel.org/linux-serial/20170206233000.3021-1-dianders@xxxxxxxxxxxx/
>
> I am not sure if reading UART_LSR is a good idea in the above patch.
> Some flags in LSR register are cleared on read (at least that's the case
> for UARTs on TI SoCs) and thus can result in loss of error/FIFO status
> information.
>
> > https://lore.kernel.org/linux-serial/1440015124-28393-1-git-send-email-california.l.sullivan@xxxxxxxxx/
>
> Looks like this never made it.

Forgot to react to the above. Yes, they never made it because I
believe due to the exact reason you mentioned above. Also California
set up different experiments IIRC and it shows that the problem didn;t
fully disappear with his approach. But maybe yours will work better
(at least it's not the first time I have seen it on different hardware
according to people's contributions).

--
With Best Regards,
Andy Shevchenko