Re: [PATCH 11/14] HID: sony: remove hid_output_raw_report calls

[David Herrmann]

Hi

On Mon, Feb 10, 2014 at 6:58 PM, Benjamin Tissoires
<benjamin.tissoires@xxxxxxxxxx> wrote:
> We can not directly change the underlying struct hid_ll_driver here
> as we did for hdev->hid_output_raw_report.
> So allocate a struct ll_driver, and replace the old one when removing
> the device.
> To get a fully functional driver, we must also split the function
> sixaxis_usb_output_raw_report() in 2, one regarding output_report, and
> the other for raw_request.

Sorry, i cannot follow here. Could you explain why this is needed? And
I also don't think you're supposed to change the ll_driver unlocked.
The real ll_driver might access it in any way. I don't think we do it
right now, but it might happen.

Why can't we introduce QUIRK flags that make HID core drop the
report_id for outgoing messages?

Thanks
David

> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
> ---
>  drivers/hid/hid-sony.c | 75 ++++++++++++++++++++++++++++++++++----------------
>  1 file changed, 52 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/hid/hid-sony.c b/drivers/hid/hid-sony.c
> index d980943..dbbcd0c8 100644
> --- a/drivers/hid/hid-sony.c
> +++ b/drivers/hid/hid-sony.c
> @@ -507,6 +507,8 @@ struct sony_sc {
>         struct work_struct state_worker;
>         struct power_supply battery;
>
> +       struct hid_ll_driver *prev_ll_driver;
> +
>  #ifdef CONFIG_SONY_FF
>         __u8 left;
>         __u8 right;
> @@ -760,38 +762,52 @@ static int sony_mapping(struct hid_device *hdev, struct hid_input *hi,
>
>  /*
>   * The Sony Sixaxis does not handle HID Output Reports on the Interrupt EP
> - * like it should according to usbhid/hid-core.c::usbhid_output_raw_report()
> + * like it should according to usbhid/hid-core.c::usbhid_output_report()
>   * so we need to override that forcing HID Output Reports on the Control EP.
> - *
> - * There is also another issue about HID Output Reports via USB, the Sixaxis
> - * does not want the report_id as part of the data packet, so we have to
> - * discard buf[0] when sending the actual control message, even for numbered
> - * reports, humpf!
>   */
> -static int sixaxis_usb_output_raw_report(struct hid_device *hid, __u8 *buf,
> -               size_t count, unsigned char report_type)
> +static int sixaxis_usb_output_report(struct hid_device *hid, __u8 *buf,
> +               size_t count)
> +{
> +       return hid_hw_raw_request(hid, buf[0], buf, count, HID_OUTPUT_REPORT,
> +               HID_REQ_SET_REPORT);
> +}
> +
> +/*
> + * There is also another issue about the SET_REPORT command via USB,
> + * the Sixaxis does not want the report_id as part of the data packet, so
> + * we have to discard buf[0] when sending the actual control message, even
> + * for numbered reports, humpf!
> + */
> +static int sixaxis_usb_raw_request(struct hid_device *hid,
> +                                  unsigned char reportnum, __u8 *buf,
> +                                  size_t len, unsigned char rtype, int reqtype)
>  {
>         struct usb_interface *intf = to_usb_interface(hid->dev.parent);
>         struct usb_device *dev = interface_to_usbdev(intf);
>         struct usb_host_interface *interface = intf->cur_altsetting;
> -       int report_id = buf[0];
>         int ret;
> +       u8 usb_dir;
> +       unsigned int usb_pipe;
>
> -       if (report_type == HID_OUTPUT_REPORT) {
> +       if (reqtype == HID_REQ_SET_REPORT) {
>                 /* Don't send the Report ID */
>                 buf++;
> -               count--;
> +               len--;
> +               usb_dir = USB_DIR_OUT;
> +               usb_pipe = usb_sndctrlpipe(dev, 0);
> +       } else {
> +               usb_dir = USB_DIR_IN;
> +               usb_pipe = usb_rcvctrlpipe(dev, 0);
>         }
>
> -       ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
> -               HID_REQ_SET_REPORT,
> -               USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
> -               ((report_type + 1) << 8) | report_id,
> -               interface->desc.bInterfaceNumber, buf, count,
> +       ret = usb_control_msg(dev, usb_pipe, reqtype,
> +               usb_dir | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
> +               ((rtype + 1) << 8) | reportnum,
> +               interface->desc.bInterfaceNumber, buf, len,
>                 USB_CTRL_SET_TIMEOUT);
>
> -       /* Count also the Report ID, in case of an Output report. */
> -       if (ret > 0 && report_type == HID_OUTPUT_REPORT)
> +       /* Count also the Report ID. */
> +       if (ret > 0 && reqtype == HID_REQ_SET_REPORT)
>                 ret++;
>
>         return ret;
> @@ -1047,7 +1063,7 @@ static void sixaxis_state_worker(struct work_struct *work)
>         buf[10] |= sc->led_state[2] << 3;
>         buf[10] |= sc->led_state[3] << 4;
>
> -       hid_output_raw_report(sc->hdev, buf, sizeof(buf), HID_OUTPUT_REPORT);
> +       hid_hw_output_report(sc->hdev, buf, sizeof(buf));
>  }
>
>  static void dualshock4_state_worker(struct work_struct *work)
> @@ -1254,6 +1270,7 @@ static int sony_probe(struct hid_device *hdev, const struct hid_device_id *id)
>         unsigned long quirks = id->driver_data;
>         struct sony_sc *sc;
>         unsigned int connect_mask = HID_CONNECT_DEFAULT;
> +       struct hid_ll_driver *ll_driver;
>
>         sc = devm_kzalloc(&hdev->dev, sizeof(*sc), GFP_KERNEL);
>         if (sc == NULL) {
> @@ -1285,13 +1302,20 @@ static int sony_probe(struct hid_device *hdev, const struct hid_device_id *id)
>         }
>
>         if (sc->quirks & SIXAXIS_CONTROLLER_USB) {
> -               hdev->hid_output_raw_report = sixaxis_usb_output_raw_report;
> +               ll_driver = devm_kzalloc(&hdev->dev, sizeof(*ll_driver),
> +                                            GFP_KERNEL);
> +               if (ll_driver == NULL)
> +                       return -ENOMEM;
> +               sc->prev_ll_driver = hdev->ll_driver;
> +               *ll_driver = *hdev->ll_driver;
> +               hdev->ll_driver = ll_driver;
> +               ll_driver->output_report = sixaxis_usb_output_report;
> +               ll_driver->raw_request = sixaxis_usb_raw_request;
>                 ret = sixaxis_set_operational_usb(hdev);
>                 INIT_WORK(&sc->state_worker, sixaxis_state_worker);
> -       }
> -       else if (sc->quirks & SIXAXIS_CONTROLLER_BT)
> +       } else if (sc->quirks & SIXAXIS_CONTROLLER_BT) {
>                 ret = sixaxis_set_operational_bt(hdev);
> -       else if (sc->quirks & DUALSHOCK4_CONTROLLER_USB) {
> +       } else if (sc->quirks & DUALSHOCK4_CONTROLLER_USB) {
>                 /* Report 5 (31 bytes) is used to send data to the controller via USB */
>                 ret = sony_set_output_report(sc, 0x05, 248);
>                 if (ret < 0)
> @@ -1339,6 +1363,8 @@ static int sony_probe(struct hid_device *hdev, const struct hid_device_id *id)
>  err_close:
>         hid_hw_close(hdev);
>  err_stop:
> +       if (sc->prev_ll_driver)
> +               hdev->ll_driver = sc->prev_ll_driver;
>         if (sc->quirks & SONY_LED_SUPPORT)
>                 sony_leds_remove(hdev);
>         if (sc->quirks & SONY_BATTERY_SUPPORT)
> @@ -1351,6 +1377,9 @@ static void sony_remove(struct hid_device *hdev)
>  {
>         struct sony_sc *sc = hid_get_drvdata(hdev);
>
> +       if (sc->prev_ll_driver)
> +               hdev->ll_driver = sc->prev_ll_driver;
> +
>         if (sc->quirks & SONY_LED_SUPPORT)
>                 sony_leds_remove(hdev);
>
> --
> 1.8.3.1
>
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