Hi Benjamin,
> When the generic hid parsing of the report descriptors in hid-core
> detects that the device contains the field ContactID, the device should
> be handled by hid-multitouch, and hid-core should release it.
> This patch implements a temporary fix for hid-core to automatically
> call the loading of hid-multitouch. A better solution would involve
> userspace.
>
> The code is inspired from what is done in the bttv module.
>
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxx>
> ---
>
> Hi guys,
>
> I finally managed to find some time to resend this patch.
Great, please find some comments inline.
> drivers/hid/hid-core.c | 33 ++++++++++++++++++++++++++++++++-
> include/linux/hid.h | 8 ++++++++
> 2 files changed, 40 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
> index 990fe19..a84221e 100644
> --- a/drivers/hid/hid-core.c
> +++ b/drivers/hid/hid-core.c
> @@ -1210,6 +1210,31 @@ static struct bin_attribute dev_bin_attr_report_desc = {
> .size = HID_MAX_DESCRIPTOR_SIZE,
> };
>
> +#if defined(CONFIG_MODULES) && defined(MODULE)
> +/* Loading of hid_multitouch. This is done from the kernel until we come up
> + * with a more robust solution. */
> +static void hid_request_hid_mt_module_async(struct work_struct *work)
> +{
> + request_module("hid-multitouch");
> +}
> +
> +static void hid_request_hid_mt_module(struct hid_device *dev)
> +{
> + dev->request_hid_mt_module = 1;
> + INIT_WORK(&dev->request_hid_mt_module_wk,
> + hid_request_hid_mt_module_async);
This init would probably be better off as a static declaration; after
all, we do not need one workqueue per hid device.
> + schedule_work(&dev->request_hid_mt_module_wk);
> +}
> +
> +static void hid_flush_request_modules(struct hid_device *dev)
> +{
> + flush_work_sync(&dev->request_hid_mt_module_wk);
> +}
> +#else
> +#define hid_request_hid_mt_module(dev)
> +#define hid_flush_request_modules(dev)
> +#endif /* CONFIG_MODULES */
> +
> int hid_connect(struct hid_device *hdev, unsigned int connect_mask)
> {
> static const char *types[] = { "Device", "Pointer", "Mouse", "Device",
> @@ -1235,7 +1260,9 @@ int hid_connect(struct hid_device *hdev, unsigned int connect_mask)
> connect_mask & HID_CONNECT_HIDINPUT_FORCE))
> hdev->claimed |= HID_CLAIMED_INPUT;
> if (hdev->quirks & HID_QUIRK_MULTITOUCH) {
> - /* this device should be handled by hid-multitouch, skip it */
> + /* this device should be handled by hid-multitouch, request
> + * for hid-multitouch to be loaded and leave the device to it */
> + hid_request_hid_mt_module(hdev);
> return -ENODEV;
> }
>
> @@ -2107,6 +2134,8 @@ struct hid_device *hid_allocate_device(void)
> INIT_LIST_HEAD(&hdev->debug_list);
> sema_init(&hdev->driver_lock, 1);
>
> + hdev->request_hid_mt_module = 0;
> +
Allocated using kzalloc, so no need.
> return hdev;
> err:
> put_device(&hdev->dev);
> @@ -2121,6 +2150,8 @@ static void hid_remove_device(struct hid_device *hdev)
> hid_debug_unregister(hdev);
> hdev->status &= ~HID_STAT_ADDED;
> }
> + if (hdev->request_hid_mt_module)
> + hid_flush_request_modules(hdev);
I would put the test inside the flush function instead, to restrict
the use of the bare variables.
> }
>
> /**
> diff --git a/include/linux/hid.h b/include/linux/hid.h
> index 3a95da6..0058ca9 100644
> --- a/include/linux/hid.h
> +++ b/include/linux/hid.h
> @@ -538,6 +538,14 @@ struct hid_device { /* device report descriptor */
> struct dentry *debug_events;
> struct list_head debug_list;
> wait_queue_head_t debug_wait;
> +
> + /* This is a temporary fix to make hid-multitouch loadable from
> + * the kernel before we come up with more robust solution
> + * (with userspace involvement).
> + * In case we detect a multitouch device through the parsing of
> + * hid-core, we request for hid-multitouch to be loaded. */
> + struct work_struct request_hid_mt_module_wk;
> + bool request_hid_mt_module;
This increases memory per hid device, which is not so nice. A static
declaration in the core module ought to suffice. Probably needs
additional locking as well.
> };
>
> static inline void *hid_get_drvdata(struct hid_device *hdev)
> --
> 1.7.7.6
>
Thanks,
Henrik
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