[PATCH][Xenial SRU] UBUNTU: SAUCE: xr-usb-serial: re-initialise baudrate after resume from S3/S4

[Shrirang Bagul]

On Wed, 2017-05-17 at 09:33 -0500, Seth Forshee wrote:
> On Fri, May 12, 2017 at 08:30:52PM +0800, Shrirang Bagul wrote:
> > BugLink: https://bugs.launchpad.net/bugs/1690362
> > 
> > The XR21V1412 ports were using the hardware power-on default of 9600bps
> > after resume from S3/S4. This patch re-initialises the baud rate and
> > fixes the re-connection issues after S3/S4.
> > 
> > Changelog:
> > Version 1B, 11/6/2015
> > Fixed Bug: The conditional logic to support kernel 3.9 was incorrect(line 396 in
> > xr_usb_serial_common.c).
> > 
> > Version 1A, 1/9/2015
> > This driver will work with any USB UART function in these Exar devices:
> >         XR21V1410/1412/1414
> >         XR21B1411
> >         XR21B1420/1422/1424
> >         XR22801/802/804
> > 
> > The source code has been tested on various Linux kernels from 3.6.x to 3.17.x.
> > This may also work with newer kernels as well.
> > 
> > Signed-off-by: Shrirang Bagul <shrirang.bagul at canonical.com>
> > ---
> >  ubuntu/xr-usb-serial/Makefile               |  3 ++-
> >  ubuntu/xr-usb-serial/xr_usb_serial_common.c | 14 ++++++++++++--
> >  2 files changed, 14 insertions(+), 3 deletions(-)
> > 
> > diff --git a/ubuntu/xr-usb-serial/Makefile b/ubuntu/xr-usb-serial/Makefile
> > index 1a323a62b348..533988cede12 100644
> > --- a/ubuntu/xr-usb-serial/Makefile
> > +++ b/ubuntu/xr-usb-serial/Makefile
> > @@ -1,6 +1,7 @@
> >  obj-m := xr_usb_serial_common.o
> >  
> > -KERNELDIR ?= /lib/modules/$(shell uname -r)/build
> > +#KERNELDIR ?= /lib/modules/$(shell uname -r)/build
> > +KERNELDIR ?=$(shell pwd)/../parts/kernel/build
> >  PWD       := $(shell pwd)
> >  
> >  EXTRA_CFLAGS	:= -DDEBUG=0
> > diff --git a/ubuntu/xr-usb-serial/xr_usb_serial_common.c b/ubuntu/xr-usb-
> > serial/xr_usb_serial_common.c
> > index 5d049855fb1a..09d21e63606e 100644
> > --- a/ubuntu/xr-usb-serial/xr_usb_serial_common.c
> > +++ b/ubuntu/xr-usb-serial/xr_usb_serial_common.c
> > @@ -1146,7 +1146,7 @@ static void xr_usb_serial_tty_set_termios(struct tty_struct
> > *tty,
> >      }
> >  
> >  		
> > -	if (memcmp(&xr_usb_serial->line, &newline, sizeof newline))
> > +	//if (memcmp(&xr_usb_serial->line, &newline, sizeof newline))
> >  	{
> >  		memcpy(&xr_usb_serial->line, &newline, sizeof newline);
> >  		/*
> > @@ -1819,11 +1819,21 @@ static int xr_usb_serial_resume(struct usb_interface
> > *intf)
> >  {
> >  	struct xr_usb_serial *xr_usb_serial = usb_get_intfdata(intf);
> >  	struct xr_usb_serial_wb *wb;
> > +#if 0	
> > +	struct tty_struct *tty = xr_usb_serial->port.tty;
> > +#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 7, 0)	
> > +	struct ktermios *termios = tty->termios;
> > +#else
> > +    struct ktermios *termios = &tty->termios;
> > +#endif
> > +#endif
> >  	int rv = 0;
> >  	int cnt;
> >  	     
> >  	xr_usb_serial_pre_setup(xr_usb_serial);
> > -	
> > +	xr_usb_serial_disable(xr_usb_serial);
> > +	xr_usb_serial_set_line(xr_usb_serial, &xr_usb_serial->line);
> > +	xr_usb_serial_enable(xr_usb_serial);	
> >  	spin_lock_irq(&xr_usb_serial->read_lock);
> >  	xr_usb_serial->susp_count -= 1;
> >  	cnt = xr_usb_serial->susp_count;
> 
> This patch is sloppy and has some obviously unrelated changes (those to
> the makefile and adding in code that is commented out). So it's not very
> nice, but for this particular driver I guess it isn't that important so
> long as the changes work. There's no comments about testing on the bug;
> I assume it has been tested?
This driver is from third party vendor and is merged as-is. It has been tested by
Canonical QA on Dell IoT gateway which sports this EXAR USB-Serial chip.