From d1d996afbd2bca3bf3c484fc1f7a738134d65207 Mon Sep 17 00:00:00 2001 From: Matthias Schiffer Date: Thu, 28 May 2020 17:47:47 +0200 Subject: tty: serial: imx: clear Ageing Timer Interrupt in handler The AGTIM flag must be cleared explicitly, otherwise the IRQ handler will be called in an endless loop. Fortunately, this issue currently doesn't affect mainline kernels in practice, as the the RX FIFO trigger level is set to 1 in UFCR. When setting the trigger level to a higher number, the issue is trivially reproducible by any RX without DMA that doesn't fill the FIFO up to the configured level. Signed-off-by: Matthias Schiffer Link: https://lore.kernel.org/r/20200528154747.14201-1-matthias.schiffer@ew.tq-group.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/imx.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/tty/serial/imx.c') diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 6b078e395931..1265e8d86d8a 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -909,6 +909,8 @@ static irqreturn_t imx_uart_int(int irq, void *dev_id) usr2 &= ~USR2_ORE; if (usr1 & (USR1_RRDY | USR1_AGTIM)) { + imx_uart_writel(sport, USR1_AGTIM, USR1); + __imx_uart_rxint(irq, dev_id); ret = IRQ_HANDLED; } -- cgit v1.2.3