On Friday, November 13, 2015 at 09:34:09 PM, Stephen Warren wrote:
From: Stephen Warren swarren@nvidia.com
When CONFIG_SYS_USB_EVENT_POLL_VIA_CONTROL_EP is enabled, use a GET_REPORT control transfer to retrieve the initial state of the keyboard. This matches the technique used to poll the keyboard state. This is useful since it eliminates the remaining use of interrupt transfers from the USB keyboard driver, which allows it to work with USB HCD that don't support interrupt transfers.
Cc: Hans de Goede hdegoede@redhat.com Signed-off-by: Stephen Warren swarren@nvidia.com
Are there any disadvantages to using control transfers over interrupt transfers? I'm not aware of any, but I assume there must be a reason that U-Boot typically uses interrupt transfers.
I initially implemented the control EP polling because I had a keyboard which had issues with interrupt transfers.
Reviewed-by: Marek Vasut marex@denx.de
common/usb_kbd.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/common/usb_kbd.c b/common/usb_kbd.c index 95912f99c767..81c4d62c632b 100644 --- a/common/usb_kbd.c +++ b/common/usb_kbd.c @@ -475,6 +475,9 @@ static int usb_kbd_probe(struct usb_device *dev, unsigned int ifnum) USB_KBD_BOOT_REPORT_SIZE, data->new, data->intinterval); if (!data->intq) { +#elif defined(CONFIG_SYS_USB_EVENT_POLL_VIA_CONTROL_EP)
- if (usb_get_report(dev, iface->desc.bInterfaceNumber,
1, 0, data->new, USB_KBD_BOOT_REPORT_SIZE) < 0) {#else if (usb_submit_int_msg(dev, data->intpipe, data->new, data->intpktsize, data->intinterval) < 0) {
Best regards, Marek Vasut