On Wed, Jan 18, 2012 at 03:34:11PM +0530, Shreshtha Kumar SAHU wrote: > > >From 0742fc49405b2a6f562981f61d93198e1595f30d Mon Sep 17 00:00:00 2001 > From: Shreshtha Kumar Sahu <shreshthakumar.sahu@xxxxxxxxxxxxxx> > Date: Tue, 17 Jan 2012 12:23:19 +0530 > Subject: [PATCH v2] amba-pl011: clear previous interrupts before request_irq > > All previous interrupts should be cleared before installing > interrupt handler i.e. before request_irq. pl011_shutdown > clears the interrupt register but there may be case where > bootloader transfers control to kernel and there are some > pending interrupts. In this case interrupt handler will get > called even before interrupt mask is enabled. > > Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxx> No sign-off, and I don't understand the problem being aluded to in the description above - particularly the last sentence. In theory, we should be prepared for the interrupt handler to be called immediately after request_irq() returns, and not have the driver misbehave because of that. Maybe a better solution would be to move request_irq() a bit later? But first, having a clearer description of the problem you're seeing would be beneficial. > --- > drivers/tty/serial/amba-pl011.c | 9 +++++++++ > 1 files changed, 9 insertions(+), 0 deletions(-) > > diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c > index 6958594..6dafaa2 100644 > --- a/drivers/tty/serial/amba-pl011.c > +++ b/drivers/tty/serial/amba-pl011.c > @@ -1381,6 +1381,15 @@ static int pl011_startup(struct uart_port *port) > uap->port.uartclk = clk_get_rate(uap->clk); > > /* > + * Clear previous interrupts before installing interrupt handler > + */ > + spin_lock_irq(&uap->port.lock); > + uap->im = 0; > + writew(uap->im, uap->port.membase + UART011_IMSC); > + writew(0xffff, uap->port.membase + UART011_ICR); > + spin_unlock_irq(&uap->port.lock); > + > + /* > * Allocate the IRQ > */ > retval = request_irq(uap->port.irq, pl011_int, 0, "uart-pl011", uap); > -- > 1.7.4.3 > -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
