Wolfgang, Is there any chance to get this feature in after Stephen explained to you?
Thanks. >-----Original Message----- >From: Stephen Warren [mailto:swar...@wwwdotorg.org] >Sent: Thursday, June 28, 2012 12:58 AM >To: Wolfgang Denk >Cc: Jim Lin; 'U-Boot@lists.denx.de'; Tom Warren >Subject: Re: [U-Boot] [PATCH 1/1] USB: EHCI: Initialize multiple USB >controllers at once > >On 06/27/2012 12:55 AM, Wolfgang Denk wrote: >> Dear Jim Lin, >> >> sending the very same message eight (8!) times doesnot make it a bit >> more convincing - on contrary. >> >> In message <4b9c9637d5087840a465bdcb251780e9e2d6eda...@hkmail02.nvidia.com> >> you wrote: >>> >>>> U-Boot is not multi-tasking, so you can always access only a single >>>> USB device at a time ayway. And it is a decoumented design principle >>>> that U-Boot must not initialize any devices it does not use itself. >>>> >>>> So why? >>> Because of this complaint and request for devices under different >>> controllers >>> to be working at same time. >> >> You make another claim here, but don't explain how this is supposed to >> work or whay the exact use case would be where this was needed. >> U-Boot will not be able to access multiple devices at the same time, >> so why would it be necessary to enable these? It should be sufficient >> to enable the controller that is responsible for the single device >> that is currently being used. >> >>> "One particularly annoying consequence of this is when you use the Seaboard >>> configuration on Springbank. >>> Seaboard selects Tegra's USB3 as "usb 0" device, which is the one you can >>> use, >>> in order not to conflict with the flashing USB port USB1. >>> However, Springbank only exposes USB1 since USB3 is used internally for the >>> USB keyboard/mouse. As such, you cannot use the USB port on Springbank under >>> U-Boot at the moment. >>> " >> >> I have to admit that I cannot make any sense from this statement. The >> only thing I understand is that you are trying to use a configuration >> for one hardware (Seaboard) on another, incompatible hardware >> (Springbank). >> >> The simple answer to this problem is: don't do that, then. > >Seaboard and Springbank are essentially the same board, and hence are >almost 100% SW compatible, so there's no problem running a Seaboard >build of U-Boot/kernel/... on Springbank. > >The primary issue here is that many boards have multiple USB ports. >Users could plug e.g. a USB->Ethernet device into any of the ports. >Requiring the user to know which port is which ID so they can issue the >correct "usb start <n>" command is painful; no other SW stack limits >itself to a single port and so most people don't have a clue which ports >are numbered what; they just want USB to work. > >The specific issue on Springbank is that there are multiple USB ports >that are useful at the essentially the same time. One of the USB ports >hosts a built-in USB keyboard (inside a sealed clamshell/netbook case), >which we would like to use for the U-boot console. Another USB port is >external, and people will plug in a USB->Ethernet dongle or USB storage >device there. so, if I need to "usb start 0" to get the keyboard, and >"usb start 1" to get USB Ethernet, then as soon as I "usb start 1" to >get the Ethernet, I've just lost the console, and am unable to interact >with U-Boot any more... -- nvpublic _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot