On Sat, 19 Nov 2016 13:01:29 +0100, Andrej Krutak wrote:

Deny userspace from using the interface concurrently.

Could you clarify more what's wrong and what you're changing?

thanks,

Takashi

Signed-off-by: Andrej Krutak dev@andree.sk

sound/usb/line6/driver.h | 1 + sound/usb/line6/podhd.c | 24 ++++++++++++++++++++++++ 2 files changed, 25 insertions(+)

diff --git a/sound/usb/line6/driver.h b/sound/usb/line6/driver.h index 7e3a3aa..5d18957 100644 --- a/sound/usb/line6/driver.h +++ b/sound/usb/line6/driver.h @@ -98,6 +98,7 @@ struct line6_properties {

int altsetting;

• unsigned ctrl_if; unsigned ep_ctrl_r; unsigned ep_ctrl_w; unsigned ep_audio_r;

diff --git a/sound/usb/line6/podhd.c b/sound/usb/line6/podhd.c index 49cd4a6..6c53b87 100644 --- a/sound/usb/line6/podhd.c +++ b/sound/usb/line6/podhd.c @@ -153,6 +153,7 @@ struct usb_line6_podhd { .rats = &podhd_ratden}, .bytes_per_channel = 3 /* SNDRV_PCM_FMTBIT_S24_3LE */ }; +static struct usb_driver podhd_driver;

static void podhd_startup_start_workqueue(unsigned long data); static void podhd_startup_workqueue(struct work_struct *work); @@ -291,8 +292,13 @@ static void podhd_disconnect(struct usb_line6 *line6) struct usb_line6_podhd *pod = (struct usb_line6_podhd *)line6;

if (pod->line6.properties->capabilities & LINE6_CAP_CONTROL) {

• struct usb_interface *intf;
  

• del_timer_sync(&pod->startup_timer); cancel_work_sync(&pod->startup_work);

• intf = usb_ifnum_to_if(line6->usbdev, pod->line6.properties->ctrl_if);
  

• usb_driver_release_interface(&podhd_driver, intf);
  

  }

}

@@ -304,10 +310,26 @@ static int podhd_init(struct usb_line6 *line6, { int err; struct usb_line6_podhd *pod = (struct usb_line6_podhd *) line6;

• struct usb_interface *intf;

  line6->disconnect = podhd_disconnect;

  if (pod->line6.properties->capabilities & LINE6_CAP_CONTROL) {

• /* claim the data interface */
  

• intf = usb_ifnum_to_if(line6->usbdev, pod->line6.properties->ctrl_if);
  

• if (!intf) {
  

• 	dev_err(pod->line6.ifcdev, "interface %d not found\n",
  

• 	        pod->line6.properties->ctrl_if);
  

• 	return -ENODEV;
  

• }
  

• err = usb_driver_claim_interface(&podhd_driver, intf, NULL);
  

• if (err != 0) {
  

• 	dev_err(pod->line6.ifcdev, "can't claim interface %d, error %d\n",
  

• 	        pod->line6.properties->ctrl_if, err);
  

• 	return err;
  

• }
  

• /* create sysfs entries: */ err = snd_card_add_dev_attr(line6->card, &podhd_dev_attr_group); if (err < 0)

@@ -406,6 +428,7 @@ static int podhd_init(struct usb_line6 *line6, .altsetting = 1, .ep_ctrl_r = 0x81, .ep_ctrl_w = 0x01,

• .ctrl_if = 1,
  

  .ep_audio_r = 0x86, .ep_audio_w = 0x02, },

@@ -417,6 +440,7 @@ static int podhd_init(struct usb_line6 *line6, .altsetting = 1, .ep_ctrl_r = 0x81, .ep_ctrl_w = 0x01,

• .ctrl_if = 1,
  

  .ep_audio_r = 0x86, .ep_audio_w = 0x02, },

-- 1.9.1

Userspace apps have to claim USB interfaces before using endpoints in them (drivers/usb/core/devio.c:checkintf()). It's a lock mechanism so that two "drivers" don't steal data from each other. Kernel drivers don't have to claim interfaces to work - but they should, to lock out userspace.

While there, fix line6_properties struct to match checkpatch.pl.

Signed-off-by: Andrej Krutak dev@andree.sk --- sound/usb/line6/driver.h | 9 +++++---- sound/usb/line6/podhd.c | 26 ++++++++++++++++++++++++++ 2 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/sound/usb/line6/driver.h b/sound/usb/line6/driver.h index 7e3a3aa..a5c2e9a 100644 --- a/sound/usb/line6/driver.h +++ b/sound/usb/line6/driver.h @@ -98,10 +98,11 @@ struct line6_properties {

int altsetting;

- unsigned ep_ctrl_r; - unsigned ep_ctrl_w; - unsigned ep_audio_r; - unsigned ep_audio_w; + unsigned int ctrl_if; + unsigned int ep_ctrl_r; + unsigned int ep_ctrl_w; + unsigned int ep_audio_r; + unsigned int ep_audio_w; };

/* Capability bits */ diff --git a/sound/usb/line6/podhd.c b/sound/usb/line6/podhd.c index 49cd4a6..6ab23e5 100644 --- a/sound/usb/line6/podhd.c +++ b/sound/usb/line6/podhd.c @@ -153,6 +153,7 @@ static struct line6_pcm_properties podx3_pcm_properties = { .rats = &podhd_ratden}, .bytes_per_channel = 3 /* SNDRV_PCM_FMTBIT_S24_3LE */ }; +static struct usb_driver podhd_driver;

static void podhd_startup_start_workqueue(unsigned long data); static void podhd_startup_workqueue(struct work_struct *work); @@ -291,8 +292,14 @@ static void podhd_disconnect(struct usb_line6 *line6) struct usb_line6_podhd *pod = (struct usb_line6_podhd *)line6;

if (pod->line6.properties->capabilities & LINE6_CAP_CONTROL) { + struct usb_interface *intf; + del_timer_sync(&pod->startup_timer); cancel_work_sync(&pod->startup_work); + + intf = usb_ifnum_to_if(line6->usbdev, + pod->line6.properties->ctrl_if); + usb_driver_release_interface(&podhd_driver, intf); } }

@@ -304,10 +311,27 @@ static int podhd_init(struct usb_line6 *line6, { int err; struct usb_line6_podhd *pod = (struct usb_line6_podhd *) line6; + struct usb_interface *intf;

line6->disconnect = podhd_disconnect;

if (pod->line6.properties->capabilities & LINE6_CAP_CONTROL) { + /* claim the data interface */ + intf = usb_ifnum_to_if(line6->usbdev, + pod->line6.properties->ctrl_if); + if (!intf) { + dev_err(pod->line6.ifcdev, "interface %d not found\n", + pod->line6.properties->ctrl_if); + return -ENODEV; + } + + err = usb_driver_claim_interface(&podhd_driver, intf, NULL); + if (err != 0) { + dev_err(pod->line6.ifcdev, "can't claim interface %d, error %d\n", + pod->line6.properties->ctrl_if, err); + return err; + } + /* create sysfs entries: */ err = snd_card_add_dev_attr(line6->card, &podhd_dev_attr_group); if (err < 0) @@ -406,6 +430,7 @@ static const struct line6_properties podhd_properties_table[] = { .altsetting = 1, .ep_ctrl_r = 0x81, .ep_ctrl_w = 0x01, + .ctrl_if = 1, .ep_audio_r = 0x86, .ep_audio_w = 0x02, }, @@ -417,6 +442,7 @@ static const struct line6_properties podhd_properties_table[] = { .altsetting = 1, .ep_ctrl_r = 0x81, .ep_ctrl_w = 0x01, + .ctrl_if = 1, .ep_audio_r = 0x86, .ep_audio_w = 0x02, },