From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
stable@vger.kernel.org
Subject: Re: [PATCH backport to 5.4 and below 1/1] serial: 8250: Flush DMA Rx on RLSI
Date: Tue, 22 Nov 2022 13:40:26 +0100 [thread overview]
Message-ID: <Y3zDOjgx8LtUMfjj@kroah.com> (raw)
In-Reply-To: <1b9ac2f-d4a7-1efd-fb6f-c7f8e014ca19@linux.intel.com>
On Mon, Nov 21, 2022 at 02:49:25PM +0200, Ilpo Järvinen wrote:
> commit 1980860e0c8299316cddaf0992dd9e1258ec9d88 upstream.
>
> Returning true from handle_rx_dma() without flushing DMA first creates
> a data ordering hazard. If DMA Rx has handled any character at the
> point when RLSI occurs, the non-DMA path handles any pending characters
> jumping them ahead of those characters that are pending under DMA.
>
> Fixes: 75df022b5f89 ("serial: 8250_dma: Fix RX handling")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Link: https://lore.kernel.org/r/20221108121952.5497-5-ilpo.jarvinen@linux.intel.com
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---
> drivers/tty/serial/8250/8250_port.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
Applied to 5.4.y only. Fails to apply to 4.9.y, 4.14.y, or 4.19.y :(
next prev parent reply other threads:[~2022-11-22 12:40 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-21 12:49 [PATCH backport to 5.4 and below 1/1] serial: 8250: Flush DMA Rx on RLSI Ilpo Järvinen
2022-11-22 12:40 ` Greg Kroah-Hartman [this message]
2022-11-22 13:14 ` [PATCH backport to 4.19 " Ilpo Järvinen
2022-11-22 15:34 ` Greg Kroah-Hartman
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