maybe not everything ist fixed in AD stepping... we have observed that on our Au1500 AD board the internal USB host only works when we set CONFIG_NONCOHERENT_IO=y. without CONFIG_NONCOHERENT_IO=y we get crashes when the used usb bandwidth gets higher. for example with an USB ethernet adapter: ping works but real traffic makes the kernel crash. usb-storage does not work at all. can you confirm this? would it be possible to use CONFIG_NONCOHERENT_IO=y only for USB, and not PCI? we have PCI cards (prism54) which only work without CONFIG_NONCOHERENT_IO, so at the moment we can either have USB host or prism54 based PCI cards... bruno On Friday 22 October 2004 16:15, Yates, John wrote: > Thank you. This indeed works. > > The CONFIG_NONCOHERENT_IO option is set by default in config-shared.in when > one selects the db1500 board (among others). Does anyone have > recommendations as to how to modify config-shared.in to give others the > option of disabling this default behavior? > > Possible places could be: > > 1. Add an override defaults sub-menu for the boards that support disabling > CONFIG_NONCOHERENT_IO. > > 2. Add a CONFIG_NONCOHERENT_IO item to the bottom of "Machine Selection" > menu. (There is already a "High Memory Support" option at the bottom of the > "machine Selection" menu.) > > 3. Add a CONFIG_NONCOHERENT_IO item to the "Override CPU options" sub-menu > (in the "CPU Selection" menu). > > 4.... > > Thanks, John > > -----Original Message----- > From: Eric DeVolder [mailto:eric.devolder@xxxxxxx] > Sent: Monday, October 18, 2004 12:28 PM > To: Yates, John > Subject: Re: Hi-Speed USB controller and au1500 > > I'm guessing that CONFIG_NONCOHERENT_IO is set which means that the > buffers used by USB are non-cached, and so the LL/SC combinations > performed by the USB stack to the structs in this non-cached area will > always fail. (Examine the MIPS LL/SC...only works to cached spaces...) > > Depending upon which version of the Au1500 you have, > CONFIG_NONCOHERENT_IO was necessary due to coherency bugs. I believe > everything should be fixed with Au1500 AD so that CONFIG_NONCOHERENT_IO > isn't needed.... > > Eric > > Yates, John wrote: > >Hello all, > > > >I am having a problem using a PCI USB 2.0 Hi-Speed controller (EHCI) with > >the dbau1500 eval kit with kernel 2.4.26. I have traced the problem down > > to a call to atomic_add() (in include/asm-mips/atomic.h) that uses > > assembly to access ll/sc registers of the mips architecture. If I > > override CPU options and disable ll/sc when configuring the kernel, > > everything works fine. However this causes the atomic_add() to use > >local_irq_save()/local_irq_restore(). I am assuming this will cause quite > > a > > >performance hit since atomic_add() gets called all over the place. I > > should > > >include that the ll/sc version of atomic_add() seems to work fine until > > the call from the usb infrastructure. > > > >Below is a code trail that leads to the call to atomic_add(): > > > > > >hub.c: usb_hub_port_connect_change() > >usb.c: usb_set_address() > >usb.c: usb_control_msg() > >usb.c: usb_internal_control_msg() > >usb.c: usb_start_wait_urb() > >usb.c: usb_submit_urb() > >usb.c: submit_urb() > >hcd.c: hcd_submit_urb() > >host/ehci-hcd.c: ehci_urb_enqueue() (urb_enqueue > >function ptr) > >host/ehci-q.c: submit_async() > >host/ehci-q.c: qh_append_tds() > >host/ehci-mem.c: qh_get() > >atomic.h atomic_inc() > >atomic.h #define atomic_inc(v) atomic_add(1,(v)) <- > >uses ll/sc > > > >To reproduce my results: > > > >Plug in a Hi-Speed USB 2.0 controller into your pci slot and boot with a > > usb > > >ehci enabled kernel. Be sure to disable the non-pci usb host that is > >built-in to the au1500 when building the kernel. (I have tried two > >controllers (NEC and ALi) with identical results.) > > > >Plug a Hi-Speed device (thumb drive or external HD) into the controller. > >(system stops responding here) > > > >Low/Full speed devices work without a problem because they use the ohci or > >uhci drivers. > > > > > >Any help or direction will be greatly appreciated. > > > >John
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