On Thu, 27 Jun 2002 09:15:25 -0700 "David Brownell" <[EMAIL PROTECTED]> wrote:
> Periodic urbs get some special treatment, "automagic resubmission" where urbs > don't get handed back to drivers in most completion callbacks. Ownership > of the URB there is in a strange "shared between drivers" state that's a > bit error-prone (among other things). You just hit it! This is the exact point, where I got __confused!__ in trying to understand the Linux USB Stack. > Again that's subject to some simplification in 2.5; > it doesn't add value, but has caused some confusion. Could you please give me some hints of what kind of simplification will it be? It won't be another __complete__ reworked of the USB Stack, will it? As I understand from Linux Network Stack: * On receiving data from wire (net): - a network driver allocates sk_buffs - hands it offer to hardware (nic) - hardware fills the buffer with data, notifies drivers that there are data accepted - drivers hands the filled up sk_buffs to network stack - and the network stack will release/deallocate the sk_buffs. * On transmitting data to wire (net): - the network stack will allocates sk_buffs - hands it over to driver, which then notifies hardware to transmit data. - on completion, hardware notifies driver, and driver will release/deallocate the sk_buffs. Just for the record (not that I wanted to change the USB Stack ;) ), what couldn't the same scheme apply to the USB Stack? So that we will have very well defined! ownership of the URB just like sk_buffs. I might have overseen something here... > Likely you mean this one. I think it's still pretty up-to-date except > that 2.5 deprecates the notion that drivers be able to allocate URB memory > directly (say, in a structure they free on device disconnect). > This is what I've been looking for. Thanks Dave! Best regards, sE -- >> S. Effendi SEffendi @ sysgo . de SYSGO Real-Time Solutions GmbH http://www.sysgo.de Am Pfaffenstein 14 Tel. +49 6136 99 48 0 55270 Klein-Winternheim - Germany Fax. +49 6136 99 48 10 ------------------------------------------------------- Sponsored by: ThinkGeek at http://www.ThinkGeek.com/ _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
