Commit 2f550553 authored by Hardik Gajjar's avatar Hardik Gajjar Committed by Greg Kroah-Hartman
Browse files

usb: gadget: f_fs: Add the missing get_alt callback 



The Apple CarLife iAP gadget has a descriptor in userspace with two
alternate settings. The host sends the set_alt request to configure
alt_setting 0 or 1, and this is verified by the subsequent get_alt
request.

This patch implements and sets the get_alt callback. Without the
get_alt callback, composite.c abruptly concludes the
USB_REQ_GET/SET_INTERFACE request, assuming only one alt setting
for the endpoint.

unlike the uvc and ncm, f_fs gadget is fully implemented in userspace,
and driver just reset the eps and generate the event. so no additional
adaptaion associated with this change is not required in set_alt callback

Signed-off-by: default avatarHardik Gajjar <hgajjar@de.adit-jv.com>
Link: https://lore.kernel.org/r/20240301124708.120394-1-hgajjar@de.adit-jv.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f7a7f80c

drivers/usb/gadget/function/f_fs.c

+19 −1
Original line number Diff line number Diff line
@@ -45,6 +45,7 @@ 
#include "configfs.h"



#define FUNCTIONFS_MAGIC	0xa647361 /* Chosen by a honest dice roll ;) */

#define MAX_ALT_SETTINGS	2		  /* Allow up to 2 alt settings to be set. */



MODULE_IMPORT_NS(DMA_BUF);
@@ -80,6 +81,7 @@ struct ffs_function { 
	short				*interfaces_nums;



	struct usb_function		function;

	int				cur_alt[MAX_CONFIG_INTERFACES];

};
@@ -103,6 +105,7 @@ static int __must_check ffs_func_eps_enable(struct ffs_function *func); 
static int ffs_func_bind(struct usb_configuration *,

			 struct usb_function *);

static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned);

static int ffs_func_get_alt(struct usb_function *f, unsigned int intf);

static void ffs_func_disable(struct usb_function *);

static int ffs_func_setup(struct usb_function *,

			  const struct usb_ctrlrequest *);
@@ -3704,6 +3707,15 @@ static void ffs_reset_work(struct work_struct *work) 
	ffs_data_reset(ffs);

}



static int ffs_func_get_alt(struct usb_function *f,

			    unsigned int interface)

{

	struct ffs_function *func = ffs_func_from_usb(f);

	int intf = ffs_func_revmap_intf(func, interface);



	return (intf < 0) ? intf : func->cur_alt[interface];

}



static int ffs_func_set_alt(struct usb_function *f,

			    unsigned interface, unsigned alt)

{
@@ -3711,6 +3723,9 @@ static int ffs_func_set_alt(struct usb_function *f, 
	struct ffs_data *ffs = func->ffs;

	int ret = 0, intf;



	if (alt > MAX_ALT_SETTINGS)

		return -EINVAL;



	if (alt != (unsigned)-1) {

		intf = ffs_func_revmap_intf(func, interface);

		if (intf < 0)
@@ -3738,8 +3753,10 @@ static int ffs_func_set_alt(struct usb_function *f, 


	ffs->func = func;

	ret = ffs_func_eps_enable(func);

	if (ret >= 0)

	if (ret >= 0) {

		ffs_event_add(ffs, FUNCTIONFS_ENABLE);

		func->cur_alt[interface] = alt;

	}

	return ret;

}
@@ -4066,6 +4083,7 @@ static struct usb_function *ffs_alloc(struct usb_function_instance *fi) 
	func->function.bind    = ffs_func_bind;

	func->function.unbind  = ffs_func_unbind;

	func->function.set_alt = ffs_func_set_alt;

	func->function.get_alt = ffs_func_get_alt;

	func->function.disable = ffs_func_disable;

	func->function.setup   = ffs_func_setup;

	func->function.req_match = ffs_func_req_match;