Re: Fwd: [PATCH] Fix default q_len for usb_f_printer gadget driver

[Peter Chen <peter.chen@nxp.com>]

On 20-12-10 02:38:13, Michael Sweet wrote:
> Peter,
> 
> I know you had signed off on this patch at the end of October, but I haven't seen anything happen with it since then.  As this is the first patch I've submitted, I don't know what else I need to do, if anything, to get it merged into the kernel sources?
> 

Add Greg and Felipe.

Hi Michael, 

Yes, I added my Reviewed-by tag at the end of Oct, but I am not the
maintainer for USB Gadget, so I can't add it to my tree.

Felipe is the maintainer of USB Gadget, the accepted patch will go to
his tree, and merge into the kernel.

Peter
      
> Thanks!
> 
> 
> > Begin forwarded message:
> > 
> > From: Michael R Sweet <msweet@msweet.org>
> > Subject: [PATCH] Fix default q_len for usb_f_printer gadget driver
> > Date: October 30, 2020 at 6:34:19 PM EDT
> > To: Felipe Balbi <balbi@kernel.org>
> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, msweet@msweet.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
> > 
> > The usb_f_printer gadget driver uses a default q_len value of *0* which prevents
> > any IO from occurring.  Moreover, once the driver is instantiated it is
> > impossible to change the q_len value.
> > 
> > The following patch uses a default q_len value of 10 which matches the legacy
> > g_printer gadget driver.  This minimizes the possibility that you end up with a
> > non-working printer gadget.  It is still possible to set the q_len to a
> > different value using the configfs path of the same name.
> > 
> > Signed-off-by: Michael R Sweet <msweet@msweet.org>
> > ---
> > drivers/usb/gadget/function/f_printer.c | 5 +++++
> > 1 file changed, 5 insertions(+)
> > 
> > diff --git a/drivers/usb/gadget/function/f_printer.c b/drivers/usb/gadget/function/f_printer.c
> > index 9c7ed2539ff7..4f3161005e4f 100644
> > --- a/drivers/usb/gadget/function/f_printer.c
> > +++ b/drivers/usb/gadget/function/f_printer.c
> > @@ -50,6 +50,8 @@
> > #define GET_PORT_STATUS		1
> > #define SOFT_RESET		2
> > 
> > +#define DEFAULT_Q_LEN		10 /* same as legacy g_printer gadget */
> > +
> > static int major, minors;
> > static struct class *usb_gadget_class;
> > static DEFINE_IDA(printer_ida);
> > @@ -1317,6 +1319,9 @@ static struct usb_function_instance *gprinter_alloc_inst(void)
> > 	opts->func_inst.free_func_inst = gprinter_free_inst;
> > 	ret = &opts->func_inst;
> > 
> > +	/* Make sure q_len is initialized, otherwise the bound device can't support read/write! */
> > +	opts->q_len = DEFAULT_Q_LEN;
> > +
> > 	mutex_lock(&printer_ida_lock);
> > 
> > 	if (ida_is_empty(&printer_ida)) {
> > --
> > 2.17.1
> > 
> 
> ________________________
> Michael Sweet
> 
> 
> 



-- 

Thanks,
Peter Chen