From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Yicong Yang <yang.yicong@picoheart.com>
Cc: ilpo.jarvinen@linux.intel.com, linux-serial@vger.kernel.org,
linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org,
jirislaby@kernel.org, geshijian@picoheart.com,
yangyang.8776@picoheart.com, yanligen@picoheart.com
Subject: Re: [PATCH] serial: 8250_dw: Prefer SRBR in bogus RX timeout workaround if available
Date: Mon, 29 Jun 2026 17:56:33 +0300 [thread overview]
Message-ID: <akKHoQOr2Vq9CA1Z@ashevche-desk.local> (raw)
In-Reply-To: <20260629075510.32854-1-yang.yicong@picoheart.com>
On Mon, Jun 29, 2026 at 03:55:10PM +0800, Yicong Yang wrote:
> The DW uart could get into the cases where a bogus RX timeout
> interrupt is asserted but no available data. This could be
> workaround by doing a bogus read.
>
> Currently the driver's using the standard RBR (receive buffer
> register) for this bogus read. However the reading of RBR
> in this case is allowed to raise a hardware error if vendor
> choose to implement in this way (our platform). It's also
> allowed to do the bogus read using SRBR (shadow RBR) for
> workaround which won't raise the hardware error. So change
> to use the SRBR to workaround the issue if it's available.
...
> /* Offsets for the DesignWare specific registers */
> +#define DW_UART_SRBR_0 0x0c /* Shadow Receive Buffer Register */
Is this a name per DesignWare databook for UART? I mean that _0 part.
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2026-06-29 14:56 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-29 7:55 [PATCH] serial: 8250_dw: Prefer SRBR in bogus RX timeout workaround if available Yicong Yang
2026-06-29 14:56 ` Andy Shevchenko [this message]
2026-06-29 15:14 ` Ilpo Järvinen
2026-06-29 15:16 ` Andy Shevchenko
2026-06-29 15:56 ` Ilpo Järvinen
2026-06-29 16:07 ` Andy Shevchenko
2026-06-30 17:51 ` Yicong Yang
2026-06-30 18:18 ` Ilpo Järvinen
2026-06-30 18:42 ` Yicong Yang
2026-07-01 8:45 ` Ilpo Järvinen
2026-07-01 16:13 ` Yicong Yang
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