Re: [PATCH v7 1/3] HID: logitech-hidpp: Support translations from short to long reports

[Benjamin Tissoires <benjamin.tissoires@redhat.com>]

Hi Mazin,

On Sun, Oct 20, 2019 at 6:41 AM Mazin Rezk <mnrzk@protonmail.com> wrote:
>
> This patch allows short reports to be translated into long reports.
>
> hidpp_validate_device now returns a u8 instead of a bool which represents
> the supported reports. The corresponding bits (i.e.
> HIDPP_REPORT_*_SUPPORTED) are set if an HID++ report is supported.
>
> If a short report is being sent and the device does not support it, it is
> instead sent as a long report.
>
> Thanks,
> Mazin
>
> Signed-off-by: Mazin Rezk <mnrzk@protonmail.com>
> ---

Yep, I like this patch much better.

I also tested the 0xb012 MX Master, and it now works like a charm :)

nitpick: can you squash the next patch into this one? Because to be
useful, this patch really need one or 2 supported devices.

Cheers,
Benjamin



>  drivers/hid/hid-logitech-hidpp.c | 25 +++++++++++++++++++------
>  1 file changed, 19 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
> index e9bba282f9c1..ee604b17514f 100644
> --- a/drivers/hid/hid-logitech-hidpp.c
> +++ b/drivers/hid/hid-logitech-hidpp.c
> @@ -49,6 +49,10 @@ MODULE_PARM_DESC(disable_tap_to_click,
>  #define HIDPP_REPORT_LONG_LENGTH               20
>  #define HIDPP_REPORT_VERY_LONG_MAX_LENGTH      64
>
> +#define HIDPP_REPORT_SHORT_SUPPORTED           BIT(0)
> +#define HIDPP_REPORT_LONG_SUPPORTED            BIT(1)
> +#define HIDPP_REPORT_VERY_LONG_SUPPORTED       BIT(2)
> +
>  #define HIDPP_SUB_ID_CONSUMER_VENDOR_KEYS      0x03
>  #define HIDPP_SUB_ID_ROLLER                    0x05
>  #define HIDPP_SUB_ID_MOUSE_EXTRA_BTNS          0x06
> @@ -183,6 +187,7 @@ struct hidpp_device {
>
>         unsigned long quirks;
>         unsigned long capabilities;
> +       u8 supported_reports;
>
>         struct hidpp_battery battery;
>         struct hidpp_scroll_counter vertical_wheel_counter;
> @@ -340,6 +345,11 @@ static int hidpp_send_rap_command_sync(struct hidpp_device *hidpp_dev,
>         struct hidpp_report *message;
>         int ret, max_count;
>
> +       /* Send as long report if short reports are not supported. */
> +       if (report_id == REPORT_ID_HIDPP_SHORT &&
> +           !(hidpp_dev->supported_reports & HIDPP_REPORT_SHORT_SUPPORTED))
> +               report_id = REPORT_ID_HIDPP_LONG;
> +
>         switch (report_id) {
>         case REPORT_ID_HIDPP_SHORT:
>                 max_count = HIDPP_REPORT_SHORT_LENGTH - 4;
> @@ -3458,10 +3468,11 @@ static int hidpp_get_report_length(struct hid_device *hdev, int id)
>         return report->field[0]->report_count + 1;
>  }
>
> -static bool hidpp_validate_device(struct hid_device *hdev)
> +static u8 hidpp_validate_device(struct hid_device *hdev)
>  {
>         struct hidpp_device *hidpp = hid_get_drvdata(hdev);
> -       int id, report_length, supported_reports = 0;
> +       int id, report_length;
> +       u8 supported_reports = 0;
>
>         id = REPORT_ID_HIDPP_SHORT;
>         report_length = hidpp_get_report_length(hdev, id);
> @@ -3469,7 +3480,7 @@ static bool hidpp_validate_device(struct hid_device *hdev)
>                 if (report_length < HIDPP_REPORT_SHORT_LENGTH)
>                         goto bad_device;
>
> -               supported_reports++;
> +               supported_reports |= HIDPP_REPORT_SHORT_SUPPORTED;
>         }
>
>         id = REPORT_ID_HIDPP_LONG;
> @@ -3478,7 +3489,7 @@ static bool hidpp_validate_device(struct hid_device *hdev)
>                 if (report_length < HIDPP_REPORT_LONG_LENGTH)
>                         goto bad_device;
>
> -               supported_reports++;
> +               supported_reports |= HIDPP_REPORT_LONG_SUPPORTED;
>         }
>
>         id = REPORT_ID_HIDPP_VERY_LONG;
> @@ -3488,7 +3499,7 @@ static bool hidpp_validate_device(struct hid_device *hdev)
>                     report_length > HIDPP_REPORT_VERY_LONG_MAX_LENGTH)
>                         goto bad_device;
>
> -               supported_reports++;
> +               supported_reports |= HIDPP_REPORT_VERY_LONG_SUPPORTED;
>                 hidpp->very_long_report_length = report_length;
>         }
>
> @@ -3536,7 +3547,9 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id)
>         /*
>          * Make sure the device is HID++ capable, otherwise treat as generic HID
>          */
> -       if (!hidpp_validate_device(hdev)) {
> +       hidpp->supported_reports = hidpp_validate_device(hdev);
> +
> +       if (!hidpp->supported_reports) {
>                 hid_set_drvdata(hdev, NULL);
>                 devm_kfree(&hdev->dev, hidpp);
>                 return hid_hw_start(hdev, HID_CONNECT_DEFAULT);
> --
> 2.23.0
>