James Bottomley writes: > On Sun, 2009-05-24 at 18:13 +0200, Mikael Pettersson wrote: > > I tried booting 2.6.30-rc7 on my old '486, but it fails miserably > > during libata/pata_legacy's device scan: > [...] > > WARNING: at drivers/ata/libata-core.c:6222 ata_host_detach+0x75/0x90() > > Modules linked in: > > Pid: 1, comm: swapper Not tainted 2.6.30-rc7 #1 > > Call Trace: > > [<c01fbb05>] ? ata_host_detach+0x75/0x90 > > [<c01fbb05>] ? ata_host_detach+0x75/0x90 > > [<c01139b5>] ? warn_slowpath_common+0x45/0x80 > > [<c01139fa>] ? warn_slowpath_null+0xa/0x10 > > [<c01fbb05>] ? ata_host_detach+0x75/0x90 > > [<c02f40e0>] ? legacy_init+0x44e/0x87f > > [<c02f3c92>] ? legacy_init+0x0/0x87f > > [<c0101021>] ? _stext+0x21/0x140 > > [<c01890ff>] ? proc_register+0x2f/0x190 > > [<c018938c>] ? create_proc_entry+0x5c/0xc0 > > [<c0135ebe>] ? register_irq_proc+0x6e/0x90 > > [<c02e6484>] ? kernel_init+0x6e/0xbf > > [<c02e6416>] ? kernel_init+0x0/0xbf > > [<c01031d7>] ? kernel_thread_helper+0x7/0x10 > > OK, so the basic problem here is that pata_legacy attaches the host, > sees if it found any devices and detaches it if none were found. With > async probing, it's not waiting until discovery is finished before > deciding it has no devices and trying the detach ... the warning is > because the detach is racing with the asynchronous probe. > > One way to fix it would be to put an async_synchronize_full() before > looking for devices (try the patch below). A better way might be to > separate libata into its own domain and only wait for that. > > James > > --- > > diff --git a/drivers/ata/pata_legacy.c b/drivers/ata/pata_legacy.c > index f72c6c5..6932e56 100644 > --- a/drivers/ata/pata_legacy.c > +++ b/drivers/ata/pata_legacy.c > @@ -48,6 +48,7 @@ > * > */ > > +#include <linux/async.h> > #include <linux/kernel.h> > #include <linux/module.h> > #include <linux/pci.h> > @@ -1028,6 +1029,7 @@ static __init int legacy_init_one(struct legacy_probe *probe) > &legacy_sht); > if (ret) > goto fail; > + async_synchronize_full(); > ld->platform_dev = pdev; > > /* Nothing found means we drop the port as its probably not there */ > Thanks, with this applied the kernel boots w/o problems. Tested-by: Mikael Pettersson <mikpe@xxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
