James Bottomley writes: > The basic problem here 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 leading to this warning: > > ata1: PATA max PIO4 cmd 0x1f0 ctl 0x3f6 irq 14 > ------------[ cut here ]------------ > 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 > ---[ end trace ef1ee36e873ae3a0 ]--- > > Because it detaches before the probe is complete. > > One way to fix it would be to put an async_synchronize_full() before looking > for devices, which this patch does. A better way might be to separate libata > into its own domain and only wait for that. It's not apparent from this description, but the bug is worse than some warnings from the kernel: the kernel hangs hard. > > Reported-by: Mikael Pettersson <mikpe@xxxxxxxx> > Signed-off-by: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> and Tested-by: Mikael Pettersson <mikpe@xxxxxxxx> > > > --- > > Index: linux-2.6/drivers/ata/pata_legacy.c > =================================================================== > --- linux-2.6.orig/drivers/ata/pata_legacy.c > +++ linux-2.6/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_sht); > if (ret) > goto fail; > + async_synchronize_full(); > ld->platform_dev = pdev; > > /* Nothing found means we drop the port as its probably not there */ > -- 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
