From: Muhammad Hamza Farooq Date: Fri, 18 Sep 2015 11:08:29 +0000 (+0200) Subject: serial: sh-sci: Redirect port interrupts to CPU _only_ when DMA stops X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=371cfed3116bc2ebd173fe55870f77ea1413edac;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git serial: sh-sci: Redirect port interrupts to CPU _only_ when DMA stops Since the DMA engine is not stopped everytime rx_timer_fn is called, the interrupts have to be redirected back to CPU only when incomplete DMA transaction is handled Signed-off-by: Muhammad Hamza Farooq Signed-off-by: Geert Uytterhoeven Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 36a11110acf4..5dcd8b382e90 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1285,12 +1285,6 @@ static void rx_timer_fn(unsigned long arg) spin_lock_irqsave(&port->lock, flags); dev_dbg(port->dev, "DMA Rx timed out\n"); - scr = serial_port_in(port, SCSCR); - if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) { - scr &= ~SCSCR_RDRQE; - enable_irq(s->irqs[SCIx_RXI_IRQ]); - } - serial_port_out(port, SCSCR, scr | SCSCR_RIE); active = sci_dma_rx_find_active(s); if (active < 0) { @@ -1315,10 +1309,18 @@ static void rx_timer_fn(unsigned long arg) tty_flip_buffer_push(&port->state->port); } - spin_unlock_irqrestore(&port->lock, flags); - if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) sci_submit_rx(s); + + /* Direct new serial port interrupts back to CPU */ + scr = serial_port_in(port, SCSCR); + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) { + scr &= ~SCSCR_RDRQE; + enable_irq(s->irqs[SCIx_RXI_IRQ]); + } + serial_port_out(port, SCSCR, scr | SCSCR_RIE); + + spin_unlock_irqrestore(&port->lock, flags); } static void sci_request_dma(struct uart_port *port)