From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Vignesh Raghavendra <vigneshr@ti.com>
Cc: "open list:SERIAL DRIVERS" <linux-serial@vger.kernel.org>,
Jan Kiszka <jan.kiszka@siemens.com>,
Tony Lindgren <tony@atomide.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jirislaby@kernel.org>,
Linux OMAP Mailing List <linux-omap@vger.kernel.org>,
Linux ARM Mailing List <linux-arm-kernel@lists.infradead.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] serial: 8250: 8250_omap: Fix possible interrupt storm
Date: Tue, 13 Jul 2021 12:13:23 +0300 [thread overview]
Message-ID: <CAHp75Vcxtk0f2KRSL8gh2mz-AYE7Kav6co8N8XMbsvtyLohG5w@mail.gmail.com> (raw)
In-Reply-To: <0ae7e313-1ed7-f1be-e8a7-edd1286277a5@ti.com>
On Tue, Jul 13, 2021 at 11:54 AM Vignesh Raghavendra <vigneshr@ti.com> 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@chromium.org/
>
> 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@intel.com/
>
> 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
WARNING: multiple messages have this Message-ID (diff)
From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Vignesh Raghavendra <vigneshr@ti.com>
Cc: "open list:SERIAL DRIVERS" <linux-serial@vger.kernel.org>,
Jan Kiszka <jan.kiszka@siemens.com>,
Tony Lindgren <tony@atomide.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jirislaby@kernel.org>,
Linux OMAP Mailing List <linux-omap@vger.kernel.org>,
Linux ARM Mailing List <linux-arm-kernel@lists.infradead.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] serial: 8250: 8250_omap: Fix possible interrupt storm
Date: Tue, 13 Jul 2021 12:13:23 +0300 [thread overview]
Message-ID: <CAHp75Vcxtk0f2KRSL8gh2mz-AYE7Kav6co8N8XMbsvtyLohG5w@mail.gmail.com> (raw)
In-Reply-To: <0ae7e313-1ed7-f1be-e8a7-edd1286277a5@ti.com>
On Tue, Jul 13, 2021 at 11:54 AM Vignesh Raghavendra <vigneshr@ti.com> 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@chromium.org/
>
> 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@intel.com/
>
> 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
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-07-13 9:14 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-11 15:19 [PATCH] serial: 8250: 8250_omap: Fix possible interrupt storm Vignesh Raghavendra
2021-05-11 15:19 ` Vignesh Raghavendra
2021-05-13 14:17 ` Greg Kroah-Hartman
2021-05-13 14:17 ` Greg Kroah-Hartman
2021-05-28 5:39 ` Tony Lindgren
2021-05-28 5:39 ` Tony Lindgren
2021-05-28 6:11 ` Vignesh Raghavendra
2021-05-28 6:11 ` Vignesh Raghavendra
2021-05-28 9:00 ` Greg Kroah-Hartman
2021-05-28 9:00 ` Greg Kroah-Hartman
2021-06-22 6:15 ` Jan Kiszka
2021-06-22 6:15 ` Jan Kiszka
2021-06-22 6:23 ` Vignesh Raghavendra
2021-06-22 6:23 ` Vignesh Raghavendra
2021-07-12 20:27 ` andy
2021-07-13 8:54 ` Vignesh Raghavendra
2021-07-13 8:54 ` Vignesh Raghavendra
2021-07-13 9:09 ` Andy Shevchenko
2021-07-13 9:09 ` Andy Shevchenko
2021-07-13 9:13 ` Andy Shevchenko [this message]
2021-07-13 9:13 ` Andy Shevchenko
2021-07-27 10:39 ` Tony Lindgren
2021-07-27 10:39 ` Tony Lindgren
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