On Mon, Oct 19, 2020 at 09:36:00AM +0000, Pany wrote:
> On Sat, Oct 17, 2020 at 8:02 PM Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
> >
> > On Sat, Oct 17, 2020 at 04:07:11PM +0000, Pany wrote:
> > > Hi,
> > >
> > > I installed fedora 32 into an SD card, with which I booted my Macbook.
> > > It had worked well before, until I upgraded the kernel from 5.8.5 to
> > > 5.8.6 [1].
> > >
> > > With kernel-5.8.6-200.fc32.x86_64.rpm [2] installed, the boot process
> > > would be stuck at "A start job is running for
> > > /dev/mapper/fedora_localhost_--live-home (<time> / no limit)" (See the
> > > photo of screen [3]).
> > >
> > > By appending "systemd.debug-shell=1" to the kernel cmdline, I saved
> > > the journal [4].
> > >
> > > This issue has been bisected to commit
> > > 53965c79c2dbdc898ffc7fdbab37e920594f5e14 ("USB: Fix device driver
> > > race")
> > >
> > > If I revert this commit, the kernel 5.8.6 would boot successfully.
> >
> > This should have been fixed in 5.8.14 or 5.8.15 (5.8.14 was released on
> > the same day that the fix was installed; I'm not sure which came first).
> > At any rate it certainly should work with the most recent 5.8.y kernel.
> >
> > Alan Stern
>
> I tried, but neither 5.8.14 nor 5.8.15 worked for me.
Hmmm. Looking at the system log you captured, it appears that the
problem the SD card reader's driver getting reprobed incorrectly. The
details aren't clear, but the log shows the device getting probed twice,
once as sdb and once as sdc. If the system tried to mount one of the
sdb partitions as the root, and then sdb disappeared, that could explain
what you see.
I don't know why this is happening. But you can try adding some
debugging messages of your own. In drivers/usb/core/driver.c, the
routine __usb_bus_reprobe_drivers() should never reach the line that
calls device_reprobe() unless the USBIP or apple-mfi-fastcharge driver
is installed -- and neither of those should be involved with the card
reader device. You can add a line saying:
dev_info(dev, "new driver %s\n", new_udriver->name);
at that point and see what it produces in the log.
Alan Stern
