On Mon, 2020-03-02 at 16:19 -0500, Farhan Khan wrote: > Hi all, > > I am trying to understand how FreeBSD's usb transfers work compared > to OpenBSD by using the rum(4) driver. I am a little confused how the > FreeBSD side works. > > On the OpenBSD side, it seems that after allocating the pipes, you > use usbd_setup_xfer and usbd_transfer(). As an example, look at > OpenBSD's /usr/src/sys/dev/usb/if_rum.c, starting on line 2027-2029, > I believe that corresponds to FreeBSD's > /usr/src/sys/dev/usb/wlan/if_rum.c, line 2607 (rum_setup_tx_list) > which goes to 807. In this function, I see that it adds rum_tx_data > (tx_data[i] to the end of tx_free. However, how does it actually send > the data? I believe this occurs in the callback functions, > specifically with the usbd_transfer_submit function, but I am not > certain how that is triggered, especially when it is triggered by the > driver, such as in a send function. > > Please assist. > Thank you! > > Links below to make it easy to follow: > OpenBSD: > https://github.com/openbsd/src/blob/2e342c845e9966c26657b08851237fc18e7b5ff5/sys/dev/usb/if_rum.c#L2024 > > FreeBSD: > 1. > https://github.com/freebsd/freebsd/blob/499b2b565264824f2139ebcb5d1c97404a17e7e6/sys/dev/usb/wlan/if_rum.c#L2607 > 2. > https://github.com/freebsd/freebsd/blob/499b2b565264824f2139ebcb5d1c97404a17e7e6/sys/dev/usb/wlan/if_rum.c#L807 >
I think you're probably looking for: https://github.com/freebsd/freebsd/blob/499b2b565264824f2139ebcb5d1c97404a17e7e6/sys/dev/usb/wlan/if_rum.c#L1623 Note that I don't know anything about the if_rum driver in general, I just know to look for occurrances of usbd_transfer_start(). -- Ian _______________________________________________ freebsd-usb@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-usb To unsubscribe, send any mail to "freebsd-usb-unsubscr...@freebsd.org"
