linux-toradex.git/drivers/char, branch v2.6.34-rc4

hvc_console: Fix race between hvc_close and hvc_remove

2010-04-08T00:16:20+00:00

I don't claim to understand the tty layer, but it seems like hvc_open and
hvc_close should be balanced in their kref reference counting.

Right now we get a kref every call to hvc_open:

        if (hp->count++ > 0) {
                tty_kref_get(tty); <----- here
                spin_unlock_irqrestore(&hp->lock, flags);
                hvc_kick();
                return 0;
        } /* else count == 0 */

        tty->driver_data = hp;

        hp->tty = tty_kref_get(tty); <------ or here if hp->count was 0

But hvc_close has:

        tty_kref_get(tty);

        if (--hp->count == 0) {
...
                /* Put the ref obtained in hvc_open() */
                tty_kref_put(tty);
...
        }

        tty_kref_put(tty);

Since the outside kref get/put balance we only do a single kref_put when
count reaches 0.

The patch below changes things to call tty_kref_put once for every
hvc_close call, and with that my machine boots fine.

Signed-off-by: Anton Blanchard 
Acked-by: Amit Shah 
Signed-off-by: Rusty Russell

virtio: disable multiport console support.

2010-04-08T00:16:19+00:00

Move MULTIPORT feature and related config changes
out of exported headers, and disable the feature
at runtime.

At this point, it seems less risky to keep code around
until we can enable it than rip it out completely.

Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Rusty Russell

virtio: console makes incorrect assumption about virtio API

2010-04-08T00:16:17+00:00

The get_buf() API sets the second arg to the number of bytes *written*
by the other side; in this case it should be zero as these are output buffers.

lguest gets this right (obviously kvm's console doesn't), resulting in
continual buildup of console writes.

Signed-off-by: Rusty Russell 
Acked-by: Amit Shah

virtio: console: Fix early_put_chars usage

2010-04-08T00:16:15+00:00

Currently early_put_chars is not used by virtio_console because it can
only be used once a port has been found, at which point it's too late
because it is no longer needed. This patch should fix it.

Acked-by: Christian Borntraeger 
Signed-off-by: Amit Shah 
Signed-off-by: Rusty Russell

frv: hide uncached_access() when pgprot_noncached is not #defined

2010-04-07T15:38:05+00:00

Hide uncached_access() when pgprot_noncached is not #defined.  This prevents
the following warning:

	  CC      drivers/char/mem.o
	drivers/char/mem.c:229: warning: 'uncached_access' defined but not used

Repairs d7d4d849b4e3acc405ec222884936800ffb26d48 ("drivers/char/mem.c:
cleanups").

Signed-off-by: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

/dev/mem: allow rewinding

2010-04-07T15:38:04+00:00

commit dcefafb6 ("/dev/mem: dont allow seek to last page") inadvertently
disabled rewinding on /dev/mem.

This broke x86info for example.

Signed-off-by: Eric Dumazet 
Acked-by: Wu Fengguang 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

vfs: rename block_fsync() to blkdev_fsync()

2010-04-07T15:38:04+00:00

Requested by hch, for consistency now it is exported.

Cc: Alexander Viro 
Cc: Anton Blanchard 
Cc: Christoph Hellwig 
Cc: Jan Kara 
Cc: Jeff Moyer 
Cc: Jens Axboe 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

raw: fsync method is now required

2010-04-07T15:38:04+00:00

Commit 148f948ba877f4d3cdef036b1ff6d9f68986706a (vfs: Introduce new
helpers for syncing after writing to O_SYNC file or IS_SYNC inode) broke
the raw driver.

We now call through generic_file_aio_write -> generic_write_sync ->
vfs_fsync_range.  vfs_fsync_range has:

        if (!fop || !fop->fsync) {
                ret = -EINVAL;
                goto out;
        }

But drivers/char/raw.c doesn't set an fsync method.

We have two options: fix it or remove the raw driver completely.  I'm
happy to do either, the fact this has been broken for so long suggests it
is rarely used.

The patch below adds an fsync method to the raw driver.  My knowledge of
the block layer is pretty sketchy so this could do with a once over.

If we instead decide to remove the raw driver, this patch might still be
useful as a backport to 2.6.33 and 2.6.32.

Signed-off-by: Anton Blanchard 
Reviewed-by: Jan Kara 
Cc: Christoph Hellwig 
Cc: Alexander Viro 
Cc: Jens Axboe 
Reviewed-by: Jeff Moyer 
Tested-by: Jeff Moyer 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

devmem: handle class_create() failure

2010-04-07T15:38:03+00:00

I hit this when we had a bug in IDR for a few days.  Basically sysfs would
fail to create new inodes since it uses an IDR and therefore class_create
would fail.

While we are unlikely to see this fail we may as well handle it instead of
oopsing.

Signed-off-by: Anton Blanchard 
Reviewed-by: Wu Fengguang 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mxser: spin_lock() => spin_lock_irq()

2010-04-07T15:38:03+00:00

This should be spin_lock_irq() to match the spin_unlock_irq().  Originally
it was a lock_kernel() but we switched everything to spin_lock_irq() last
November.

[akpm@linux-foundation.org: fix the MOXA_ASPP_MON case too (per Jiri)]
Signed-off-by: Dan Carpenter 
Cc: Jiri Slaby 
Cc: Alan Cox 
Cc: Greg KH 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds