On Thu, Jan 05, 2017 at 04:40:16PM +0000, One Thousand Gnomes wrote: > On Thu, 5 Jan 2017 13:48:40 -0200 > Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxx> wrote: > > > Ted T'so has added the function size_fifo in 1999 for the 2.3 series > > [1], a long time ago. > > > > During the 2.5 cycle, Russell King has restructured the serial drivers > > and, in that process, has suggested using schedule_timeout instead of > > mdelay in size_fifo. [2] > > > > It was only at 2.6.7 that Greg Kroah-Hartman added the msleep function > > to the core kernel, as people were starting to duplicate it. [3] > > > > However, as size_fifo is called under a spinlock from the autoconfig > > function, we might not use msleep here, so removing that comment is the > > appropriate thing to do. > > No.. it's still a flaw in the driver that we can't use msleep here. It's > one of those things that people want to know if the probe locking ever > gets restructured. > > Alan Okay. At first, I wanted to simply use msleep there, then realized there was the spinlock. I thought I got a good writeup of the history that was not in git yet, maybe we should just add a better comment and more details in the commit log. How about this as the comment? Cascardo. --- diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 1731b98d2471..51efbfcfb922 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -796,7 +796,8 @@ static int size_fifo(struct uart_8250_port *up) serial_out(up, UART_LCR, 0x03); for (count = 0; count < 256; count++) serial_out(up, UART_TX, count); - mdelay(20);/* FIXME - schedule_timeout */ + /* FIXME - use msleep when probe locking is restructured */ + mdelay(20); for (count = 0; (serial_in(up, UART_LSR) & UART_LSR_DR) && (count < 256); count++) serial_in(up, UART_RX); -- 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
