Messages in this thread | | | From | Andrew Jeffery <> | Subject | [PATCH v2 0/2] serial: 8250: Mitigate Tx stall risk for Aspeed VUARTs | Date | Wed, 19 May 2021 09:37:02 +0930 |
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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
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