On Sun, Jun 28, 2015 at 09:11:30AM +0530, Jayan John wrote: > On Sun, Jun 28, 2015 at 5:34 AM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > On Sat, 27 Jun 2015, Jayan John wrote: > > > >> Thanks. > >> > >> Yes, the wLength value in the Setup packet is equal to 64. "Aligned" > >> was the wrong term, multiple of 64 would be more appropriate :). > >> > >> The hid gadget driver queues a request for the transfer. Please see below logs.. > >> ... > >> HID: drivers/usb/gadget/f_hid_meu.c:366 - hidg_setup() > >> HID: hid_setup crtl_request : bRequestType:0x21 bRequest:0x9 Value:0x200 > > > > What driver is this? I don't see drivers/usb/gadget/f_hid_meu.c in > > 4.1. I do see drivers/usb/gadget/function/f_hid.c, but in > > that driver the hidg_setup() routine does this: > > > > case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8 > > | HID_REQ_SET_REPORT): > > VDBG(cdev, "set_report | wLength=%d\n", ctrl->wLength); > > goto stall; > > break; > > > > Thus, it doesn't handle Set Report at all. > > > This is a modified f_hid.c i.e. uses a single Interrupt IN endpoint > and control ep0 for in and out transfers. The source is the same as > f_hid.c before the integration of the Interrupt OUT patch "usb: > gadget: hidg: register OUT INT endpoint for SET_REPORT". See > https://github.com/torvalds/linux/commit/99c515005857ff7d6cd5c2ba272ccab5dc0ea648 > > >> HID: drivers/usb/chipidea/udc.c:1337 - ep_queue() > >> HID: drivers/usb/chipidea/udc.c:794 - _ep_queue() > >> HID: drivers/usb/chipidea/udc.c:467 - _hardware_enqueue() > >> HID: drivers/usb/chipidea/udc.c:395 - add_td_to_list() > >> HID: drivers/usb/chipidea/udc.c:61 - hw_ep_bit() > >> HID: drivers/usb/chipidea/udc.c:209 - hw_ep_prime() > >> .. > >> > >> > >> In the 64 bytes case, the following logs are missing (indicating > >> transfer complete interrupt): > >> ... > >> HID: drivers/usb/chipidea/core.c:368 - ci_irq() > >> HID: drivers/usb/chipidea/udc.c:1786 - udc_irq() > >> HID: drivers/usb/chipidea/udc.c:282 - hw_read_intr_status() > >> HID: drivers/usb/chipidea/udc.c:271 - hw_read_intr_enable() > >> HID: drivers/usb/chipidea/udc.c:309 - hw_test_and_clear_intr_active() > >> HID: drivers/usb/chipidea/udc.c:992 - isr_tr_complete_handler() > >> HID: drivers/usb/chipidea/udc.c:295 - hw_test_and_clear_complete() > >> HID: drivers/usb/chipidea/udc.c:68 - ep_to_bit() > >> HID: drivers/usb/chipidea/udc.c:957 - isr_tr_complete_low() > >> HID: drivers/usb/chipidea/udc.c:583 - _hardware_dequeue() > >> HID: drivers/usb/gadget/f_hid_meu.c:322 - hidg_set_report_complete() > >> ... > > > > Assuming the ep_queue() was for a 64-byte transfer, this indicates > > there is a bug in the chipidea UDC driver or hardware. > > > > Alan Stern > > > > If this is a bug in the chipidea UDC driver or hardware, how can I > address this i.e. register an errata? I am hoping this is something > Peter might be able to help with. > Just like Steve pointed, it should be a ZLT problem, do you have below patch in your tree, and the host may not send zlt, but you may queue an zero-length request, the f_hid does not set req->zero flag either. commit 953c66469735aed8d2ada639a72b150f01dae605 Author: Abbas Raza <Abbas_Raza@xxxxxxxxxx> Date: Thu Jul 17 19:34:31 2014 +0800 usb: chipidea: udc: Disable auto ZLP generation on ep0 If it still has problem, send me apps if possible (with needed kernel patches). -- Best Regards, Peter Chen -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
