tmakin/ack-tegra
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

serial: amba-pl011: Fix RX stall when DMA is used

Browse Source 
commit 2bcacc1c87acf9a8ebc17de18cb2b3cfeca547cf upstream.

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: 211565b100 ("serial: pl011: UPSTAT_AUTORTS requires .throttle/unthrottle")
Cc: stable@vger.kernel.org
Signed-off-by: Kartik Rajput <kkartik@nvidia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20241113092629.60226-1-kkartik@nvidia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Kartik Rajput
2024-11-13 14:56:29 +05:30
committed by Greg Kroah-Hartman
parent ac0e4f5f76
commit e881c8f0a7
1 changed files with 5 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
drivers/tty/serial/amba-pl011.c
View File

@@ -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);
}