Re: [PATCH USB] usb: raw-gadget: support stalling/halting/wedging endpoints

From: Andrey Konovalov
Date: Wed Apr 29 2020 - 21:10:13 EST


On Thu, Apr 30, 2020 at 3:08 AM Andrey Konovalov <andreyknvl@xxxxxxxxxx> wrote:
>
> Raw Gadget is currently unable to stall/halt/wedge gadget endpoints,
> which is required for proper emulation of certain USB classes.
>
> This patch adds a few more ioctls:
>
> - USB_RAW_IOCTL_EP0_STALL allows to stall control endpoint #0 when
> there's a pending setup request for it.
> - USB_RAW_IOCTL_SET/CLEAR_HALT/WEDGE allow to set/clear halt/wedge status
> on non-control non-isochronous endpoints.
>
> Fixes: f2c2e717642c ("usb: gadget: add raw-gadget interface")
> Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
> ---
>
> This goes on top of:
>
> [PATCH v2] usb: raw-gadget: fix gadget endpoint selection
>
> which in turns goes on top of:
>
> [PATCH USB v2 1/2] usb: raw-gadget: fix return value of ep read ioctls
> [PATCH USB v2 2/2] usb: raw-gadget: fix typo in uapi headers
>
> ---
> Documentation/usb/raw-gadget.rst | 2 -
> drivers/usb/gadget/legacy/raw_gadget.c | 131 ++++++++++++++++++++++++-
> include/uapi/linux/usb/raw_gadget.h | 15 +++
> 3 files changed, 144 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/usb/raw-gadget.rst b/Documentation/usb/raw-gadget.rst
> index 42bd446d72b2..f70aa635e11d 100644
> --- a/Documentation/usb/raw-gadget.rst
> +++ b/Documentation/usb/raw-gadget.rst
> @@ -49,8 +49,6 @@ The typical usage of Raw Gadget looks like:
> Potential future improvements
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> -- Implement ioctl's for setting/clearing halt status on endpoints.
> -
> - Reporting more events (suspend, resume, etc.) through
> USB_RAW_IOCTL_EVENT_FETCH.
>
> diff --git a/drivers/usb/gadget/legacy/raw_gadget.c b/drivers/usb/gadget/legacy/raw_gadget.c
> index e6abbc15341a..9ceeecac5ee0 100644
> --- a/drivers/usb/gadget/legacy/raw_gadget.c
> +++ b/drivers/usb/gadget/legacy/raw_gadget.c
> @@ -204,7 +204,7 @@ static void dev_free(struct kref *kref)
> }
> raw_event_queue_destroy(&dev->queue);
> for (i = 0; i < dev->eps_num; i++) {
> - if (dev->eps[i].state != STATE_EP_ENABLED)
> + if (dev->eps[i].state == STATE_EP_DISABLED)
> continue;
> usb_ep_disable(dev->eps[i].ep);
> usb_ep_free_request(dev->eps[i].ep, dev->eps[i].req);
> @@ -704,6 +704,50 @@ static int raw_ioctl_ep0_read(struct raw_dev *dev, unsigned long value)
> return ret;
> }
>
> +static int raw_ioctl_ep0_stall(struct raw_dev *dev, unsigned long value)
> +{
> + int ret = 0;
> + unsigned long flags;
> +
> + if (value)
> + return -EINVAL;
> + spin_lock_irqsave(&dev->lock, flags);
> + if (dev->state != STATE_DEV_RUNNING) {
> + dev_dbg(dev->dev, "fail, device is not running\n");
> + ret = -EINVAL;
> + goto out_unlock;
> + }
> + if (!dev->gadget) {
> + dev_dbg(dev->dev, "fail, gadget is not bound\n");
> + ret = -EBUSY;
> + goto out_unlock;
> + }
> + if (dev->ep0_urb_queued) {
> + dev_dbg(&dev->gadget->dev, "fail, urb already queued\n");
> + ret = -EBUSY;
> + goto out_unlock;
> + }
> + if (!dev->ep0_in_pending && !dev->ep0_out_pending) {
> + dev_dbg(&dev->gadget->dev, "fail, no request pending\n");
> + ret = -EBUSY;
> + goto out_unlock;
> + }
> +
> + ret = usb_ep_set_halt(dev->gadget->ep0);
> + if (ret < 0)
> + dev_err(&dev->gadget->dev,
> + "fail, usb_ep_set_halt returned %d\n", ret);
> +
> + if (dev->ep0_in_pending)
> + dev->ep0_in_pending = false;
> + else
> + dev->ep0_out_pending = false;
> +
> +out_unlock:
> + spin_unlock_irqrestore(&dev->lock, flags);
> + return ret;
> +}
> +
> static int raw_ioctl_ep_enable(struct raw_dev *dev, unsigned long value)
> {
> int ret = 0, i;
> @@ -810,7 +854,7 @@ static int raw_ioctl_ep_disable(struct raw_dev *dev, unsigned long value)
> ret = -EBUSY;
> goto out_unlock;
> }
> - if (dev->eps[i].state != STATE_EP_ENABLED) {
> + if (dev->eps[i].state == STATE_EP_DISABLED) {
> dev_dbg(&dev->gadget->dev, "fail, endpoint is not enabled\n");
> ret = -EINVAL;
> goto out_unlock;
> @@ -848,6 +892,74 @@ static int raw_ioctl_ep_disable(struct raw_dev *dev, unsigned long value)
> return ret;
> }
>
> +static int raw_ioctl_ep_set_clear_halt_wedge(struct raw_dev *dev,
> + unsigned long value, bool set, bool halt)
> +{
> + int ret = 0, i = value;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&dev->lock, flags);
> + if (dev->state != STATE_DEV_RUNNING) {
> + dev_dbg(dev->dev, "fail, device is not running\n");
> + ret = -EINVAL;
> + goto out_unlock;
> + }
> + if (!dev->gadget) {
> + dev_dbg(dev->dev, "fail, gadget is not bound\n");
> + ret = -EBUSY;
> + goto out_unlock;
> + }
> + if (i < 0 || i >= dev->eps_num) {
> + dev_dbg(dev->dev, "fail, invalid endpoint\n");
> + ret = -EBUSY;
> + goto out_unlock;
> + }
> + if (dev->eps[i].state == STATE_EP_DISABLED) {
> + dev_dbg(&dev->gadget->dev, "fail, endpoint is not enabled\n");
> + ret = -EINVAL;
> + goto out_unlock;
> + }
> + if (dev->eps[i].disabling) {
> + dev_dbg(&dev->gadget->dev,
> + "fail, disable is in progress\n");
> + ret = -EINVAL;
> + goto out_unlock;
> + }
> + if (dev->eps[i].urb_queued) {
> + dev_dbg(&dev->gadget->dev,
> + "fail, waiting for urb completion\n");
> + ret = -EINVAL;
> + goto out_unlock;
> + }
> + if (usb_endpoint_xfer_isoc(dev->eps[i].ep->desc)) {
> + dev_dbg(&dev->gadget->dev,
> + "fail, can't halt/wedge ISO endpoint\n");
> + ret = -EINVAL;
> + goto out_unlock;
> + }
> +
> + if (set && halt) {
> + ret = usb_ep_set_halt(dev->eps[i].ep);
> + if (ret < 0)
> + dev_err(&dev->gadget->dev,
> + "fail, usb_ep_set_halt returned %d\n", ret);
> + } else if (!set && halt) {
> + ret = usb_ep_clear_halt(dev->eps[i].ep);
> + if (ret < 0)
> + dev_err(&dev->gadget->dev,
> + "fail, usb_ep_clear_halt returned %d\n", ret);
> + } else if (set && !halt) {
> + ret = usb_ep_set_wedge(dev->eps[i].ep);
> + if (ret < 0)
> + dev_err(&dev->gadget->dev,
> + "fail, usb_ep_set_wedge returned %d\n", ret);
> + }
> +
> +out_unlock:
> + spin_unlock_irqrestore(&dev->lock, flags);
> + return ret;
> +}
> +
> static void gadget_ep_complete(struct usb_ep *ep, struct usb_request *req)
> {
> struct raw_ep *r_ep = (struct raw_ep *)ep->driver_data;
> @@ -1144,6 +1256,21 @@ static long raw_ioctl(struct file *fd, unsigned int cmd, unsigned long value)
> case USB_RAW_IOCTL_EPS_INFO:
> ret = raw_ioctl_eps_info(dev, value);
> break;
> + case USB_RAW_IOCTL_EP0_STALL:
> + ret = raw_ioctl_ep0_stall(dev, value);
> + break;
> + case USB_RAW_IOCTL_EP_SET_HALT:
> + ret = raw_ioctl_ep_set_clear_halt_wedge(
> + dev, value, true, true);
> + break;
> + case USB_RAW_IOCTL_EP_CLEAR_HALT:
> + ret = raw_ioctl_ep_set_clear_halt_wedge(
> + dev, value, false, true);
> + break;
> + case USB_RAW_IOCTL_EP_SET_WEDGE:
> + ret = raw_ioctl_ep_set_clear_halt_wedge(
> + dev, value, true, false);
> + break;
> default:
> ret = -EINVAL;
> }
> diff --git a/include/uapi/linux/usb/raw_gadget.h b/include/uapi/linux/usb/raw_gadget.h
> index 722124fff290..12ed9fa9ad97 100644
> --- a/include/uapi/linux/usb/raw_gadget.h
> +++ b/include/uapi/linux/usb/raw_gadget.h
> @@ -244,4 +244,19 @@ struct usb_raw_eps_info {
> */
> #define USB_RAW_IOCTL_EPS_INFO _IOR('U', 11, struct usb_raw_eps_info)
>
> +/*
> + * Stalls a pending control request on endpoint 0.
> + * Returns 0 on success or negative error code on failure.
> + */
> +#define USB_RAW_IOCTL_EP0_STALL _IO('U', 12)
> +
> +/*
> + * Sets or clears halt or wedge status of the endpoint.
> + * Accepts endpoint handle as an argument.
> + * Returns 0 on success or negative error code on failure.
> + */
> +#define USB_RAW_IOCTL_EP_SET_HALT _IOW('U', 12, __u32)

Eh, messed up ioctl numbers, will send v2 shortly.

> +#define USB_RAW_IOCTL_EP_CLEAR_HALT _IOW('U', 13, __u32)
> +#define USB_RAW_IOCTL_EP_SET_WEDGE _IOW('U', 14, __u32)
> +
> #endif /* _UAPI__LINUX_USB_RAW_GADGET_H */
> --
> 2.26.2.303.gf8c07b1a785-goog
>