From: Andrew Jeffery <andrew@aj.id.au>
To: linux-serial@vger.kernel.org
Cc: gregkh@linuxfoundation.org, jirislaby@kernel.org, joel@jms.id.au,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-aspeed@lists.ozlabs.org, openbmc@lists.ozlabs.org,
jenmin_yuan@aspeedtech.com, ryan_chen@aspeedtech.com,
miltonm@us.ibm.com
Subject: [PATCH v2 0/2] serial: 8250: Mitigate Tx stall risk for Aspeed VUARTs
Date: Wed, 19 May 2021 09:37:02 +0930 [thread overview]
Message-ID: <20210519000704.3661773-1-andrew@aj.id.au> (raw)
Hello,
Briefly, the series works around a hardware race condition in the Tx path for
Aspeed virtual UARTs. A write burst to THR on the APB interface may provoke a
transfer stall where LSR[DR] on the LPC interface remains clear despite the
presence of data in the Rx FIFO.
For the work-around patch, v2 addresses the request for a comment about the use
of serial_in():
https://lore.kernel.org/lkml/d7918dcf-b938-498c-a012-3d93a748431b@www.fastmail.com/T/#md75702fbc3704bd4b375f1251a1415bcddea26a3
The second patch addresses the request for use of BIT() instead of an explicit
shift by converting all of the UART_{CAP,BUG}_* macros.
Please review!
Andrew
Andrew Jeffery (2):
serial: 8250: Add UART_BUG_TXRACE workaround for Aspeed VUART
serial: 8250: Use BIT(x) for UART_{CAP,BUG}_*
drivers/tty/serial/8250/8250.h | 32 +++++++++++----------
drivers/tty/serial/8250/8250_aspeed_vuart.c | 1 +
drivers/tty/serial/8250/8250_port.c | 10 +++++++
3 files changed, 28 insertions(+), 15 deletions(-)
--
2.30.2
next reply other threads:[~2021-05-19 0:07 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-19 0:07 Andrew Jeffery [this message]
2021-05-19 0:07 ` [PATCH v2 1/2] serial: 8250: Add UART_BUG_TXRACE workaround for Aspeed VUART Andrew Jeffery
2021-05-19 0:58 ` Joel Stanley
2021-05-19 4:58 ` Andrew Jeffery
2021-05-19 6:10 ` Jiri Slaby
2021-05-19 0:07 ` [PATCH v2 2/2] serial: 8250: Use BIT(x) for UART_{CAP,BUG}_* Andrew Jeffery
2021-05-19 6:14 ` Jiri Slaby
2021-05-19 6:27 ` Andrew Jeffery
2021-05-19 6:32 ` Jiri Slaby
2021-05-19 6:35 ` Andrew Jeffery
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