[PATCH] OMAP/serial: Revert bad fix of Rx FIFO threshold granularity

[PATCH] OMAP/serial: Revert bad fix of Rx FIFO threshold granularity

[Alexey Pelykh]

From: Alexey Pelykh <alexey.pelykh@gmail.com>

Partially reverts 1776fd059c40907297d6c26c51876575d63fd9e2
that introduced regression reported by Paul Walmsley.

This commit restores setting granularity in SCR register
and adds note about comments below being inconsistent with
actual code.

Signed-off-by: Alexey Pelykh <alexey.pelykh@gmail.com>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Felipe Balbi <balbi@ti.com>
Cc: linux-serial at vger.kernel.org 
Cc: linux-arm-kernel at lists.infradead.org 
Cc: linux-omap at vger.kernel.org 

---

Paul, please confirm that this patch solves the regression.

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 4dc4140..30d4f7a 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -886,6 +886,17 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 	serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
 	/* FIFO ENABLE, DMA MODE */
 
+	up->scr |= OMAP_UART_SCR_RX_TRIG_GRANU1_MASK;
+	/*
+	 * NOTE: Setting OMAP_UART_SCR_RX_TRIG_GRANU1_MASK
+	 * sets Enables the granularity of 1 for TRIGGER RX
+	 * level. Along with setting RX FIFO trigger level
+	 * to 1 (as noted below, 16 characters) and TLR[3:0]
+	 * to zero this will result RX FIFO threshold level
+	 * to 1 character, instead of 16 as noted in comment
+	 * below.
+	 */
+
 	/* Set receive FIFO threshold to 16 characters and
 	 * transmit FIFO threshold to 16 spaces
 	 */

[PATCH] OMAP/serial: Revert bad fix of Rx FIFO threshold granularity

[Paul Walmsley]

Hi Greg, Alexey,

On Wed, 3 Apr 2013, Alexey Pelykh wrote:

> From: Alexey Pelykh <alexey.pelykh@gmail.com>
> 
> Partially reverts 1776fd059c40907297d6c26c51876575d63fd9e2
> that introduced regression reported by Paul Walmsley.
> 
> This commit restores setting granularity in SCR register
> and adds note about comments below being inconsistent with
> actual code.
> 
> Signed-off-by: Alexey Pelykh <alexey.pelykh@gmail.com>
> Cc: Paul Walmsley <paul@pwsan.com>
> Cc: Kevin Hilman <khilman@linaro.org>
> Cc: Felipe Balbi <balbi@ti.com>
> Cc: linux-serial at vger.kernel.org 
> Cc: linux-arm-kernel at lists.infradead.org 
> Cc: linux-omap at vger.kernel.org 

Tested-by: Paul Walmsley <paul@pwsan.com>

Thanks for the fast response and fix, Alexey.

Greg, is it possible for you to take this for v3.9-rc fixes?


- Paul

[PATCH] OMAP/serial: Revert bad fix of Rx FIFO threshold granularity

[Greg KH]

On Wed, Apr 03, 2013 at 08:16:18PM +0000, Paul Walmsley wrote:
> Hi Greg, Alexey,
> 
> On Wed, 3 Apr 2013, Alexey Pelykh wrote:
> 
> > From: Alexey Pelykh <alexey.pelykh@gmail.com>
> > 
> > Partially reverts 1776fd059c40907297d6c26c51876575d63fd9e2
> > that introduced regression reported by Paul Walmsley.
> > 
> > This commit restores setting granularity in SCR register
> > and adds note about comments below being inconsistent with
> > actual code.
> > 
> > Signed-off-by: Alexey Pelykh <alexey.pelykh@gmail.com>
> > Cc: Paul Walmsley <paul@pwsan.com>
> > Cc: Kevin Hilman <khilman@linaro.org>
> > Cc: Felipe Balbi <balbi@ti.com>
> > Cc: linux-serial at vger.kernel.org 
> > Cc: linux-arm-kernel at lists.infradead.org 
> > Cc: linux-omap at vger.kernel.org 
> 
> Tested-by: Paul Walmsley <paul@pwsan.com>
> 
> Thanks for the fast response and fix, Alexey.
> 
> Greg, is it possible for you to take this for v3.9-rc fixes?

Will do, thanks.

greg k-h