From: Kartik Rajput Date: Wed, 13 Nov 2024 09:26:29 +0000 (+0530) Subject: serial: amba-pl011: Fix RX stall when DMA is used X-Git-Tag: v6.13-rc1~25^2~6 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=2bcacc1c87acf9a8ebc17de18cb2b3cfeca547cf;p=thirdparty%2Flinux.git serial: amba-pl011: Fix RX stall when DMA is used Function pl011_throttle_rx() calls pl011_stop_rx() to disable RX, which also disables the RX DMA by clearing the RXDMAE bit of the DMACR register. However, to properly unthrottle RX when DMA is used, the function pl011_unthrottle_rx() is expected to set the RXDMAE bit of the DMACR register, which it currently lacks. This causes RX to stall after the throttle API is called. Set RXDMAE bit in the DMACR register while unthrottling RX if RX DMA is used. Fixes: 211565b10099 ("serial: pl011: UPSTAT_AUTORTS requires .throttle/unthrottle") Cc: stable@vger.kernel.org Signed-off-by: Kartik Rajput Reviewed-by: Linus Walleij Link: https://lore.kernel.org/r/20241113092629.60226-1-kkartik@nvidia.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index 56e587b948235..2facdbcd73eb1 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -1819,6 +1819,11 @@ static void pl011_unthrottle_rx(struct uart_port *port) pl011_write(uap->im, uap, REG_IMSC); + if (uap->using_rx_dma) { + uap->dmacr |= UART011_RXDMAE; + pl011_write(uap->dmacr, uap, REG_DMACR); + } + uart_port_unlock_irqrestore(&uap->port, flags); }