linux-stable.git/drivers/tty, branch v4.14.166 Linux kernel stable tree tty: serial: pch_uart: correct usage of dma_unmap_sg 2020-01-17T18:45:50+00:00 Peng Fan peng.fan@nxp.com 2019-11-13T05:37:42+00:00 77f33d715584a86c28758a36cd796dc5e5e592c9 commit 74887542fdcc92ad06a48c0cca17cdf09fc8aa00 upstream. Per Documentation/DMA-API-HOWTO.txt, To unmap a scatterlist, just call: dma_unmap_sg(dev, sglist, nents, direction); .. note:: The 'nents' argument to the dma_unmap_sg call must be the _same_ one you passed into the dma_map_sg call, it should _NOT_ be the 'count' value _returned_ from the dma_map_sg call. However in the driver, priv->nent is directly assigned with value returned from dma_map_sg, and dma_unmap_sg use priv->nent for unmap, this breaks the API usage. So introduce a new entry orig_nent to remember 'nents'. Fixes: da3564ee027e ("pch_uart: add multi-scatter processing") Signed-off-by: Peng Fan <peng.fan@nxp.com> Link: https://lore.kernel.org/r/1573623259-6339-1-git-send-email-peng.fan@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 74887542fdcc92ad06a48c0cca17cdf09fc8aa00 upstream.

Per Documentation/DMA-API-HOWTO.txt,
To unmap a scatterlist, just call:
	dma_unmap_sg(dev, sglist, nents, direction);

.. note::

	The 'nents' argument to the dma_unmap_sg call must be
	the _same_ one you passed into the dma_map_sg call,
	it should _NOT_ be the 'count' value _returned_ from the
	dma_map_sg call.

However in the driver, priv->nent is directly assigned with value
returned from dma_map_sg, and dma_unmap_sg use priv->nent for unmap,
this breaks the API usage.

So introduce a new entry orig_nent to remember 'nents'.

Fixes: da3564ee027e ("pch_uart: add multi-scatter processing")
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/1573623259-6339-1-git-send-email-peng.fan@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: serial: imx: use the sg count from dma_map_sg 2020-01-17T18:45:50+00:00 Peng Fan peng.fan@nxp.com 2019-11-07T06:42:53+00:00 9eee44f069bd76481598013c53e65ecd385d7438 commit 596fd8dffb745afcebc0ec6968e17fe29f02044c upstream. The dmaengine_prep_slave_sg needs to use sg count returned by dma_map_sg, not use sport->dma_tx_nents, because the return value of dma_map_sg is not always same with "nents". Fixes: b4cdc8f61beb ("serial: imx: add DMA support for imx6q") Signed-off-by: Peng Fan <peng.fan@nxp.com> Link: https://lore.kernel.org/r/1573108875-26530-1-git-send-email-peng.fan@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 596fd8dffb745afcebc0ec6968e17fe29f02044c upstream.

The dmaengine_prep_slave_sg needs to use sg count returned
by dma_map_sg, not use sport->dma_tx_nents, because the return
value of dma_map_sg is not always same with "nents".

Fixes: b4cdc8f61beb ("serial: imx: add DMA support for imx6q")
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/1573108875-26530-1-git-send-email-peng.fan@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: always relink the port 2020-01-14T19:05:45+00:00 Sudip Mukherjee sudipm.mukherjee@gmail.com 2019-12-27T17:44:34+00:00 292c7f12b2b986f84a612d9f623334e48aacce8f commit 273f632912f1b24b642ba5b7eb5022e43a72f3b5 upstream. If the serial device is disconnected and reconnected, it re-enumerates properly but does not link it. fwiw, linking means just saving the port index, so allow it always as there is no harm in saving the same value again even if it tries to relink with the same port. Fixes: fb2b90014d78 ("tty: link tty and port before configuring it as console") Reported-by: Kenneth R. Crudup <kenny@panix.com> Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191227174434.12057-1-sudipm.mukherjee@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 273f632912f1b24b642ba5b7eb5022e43a72f3b5 upstream.

If the serial device is disconnected and reconnected, it re-enumerates
properly but does not link it. fwiw, linking means just saving the port
index, so allow it always as there is no harm in saving the same value
again even if it tries to relink with the same port.

Fixes: fb2b90014d78 ("tty: link tty and port before configuring it as console")
Reported-by: Kenneth R. Crudup <kenny@panix.com>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191227174434.12057-1-sudipm.mukherjee@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: link tty and port before configuring it as console 2020-01-14T19:05:45+00:00 Sudip Mukherjee sudipm.mukherjee@gmail.com 2019-12-12T13:16:02+00:00 3d7cbd45ae237bcc958b79cf6bb70d0e1052ca41 commit fb2b90014d782d80d7ebf663e50f96d8c507a73c upstream. There seems to be a race condition in tty drivers and I could see on many boot cycles a NULL pointer dereference as tty_init_dev() tries to do 'tty->port->itty = tty' even though tty->port is NULL. 'tty->port' will be set by the driver and if the driver has not yet done it before we open the tty device we can get to this situation. By adding some extra debug prints, I noticed that: 6.650130: uart_add_one_port 6.663849: register_console 6.664846: tty_open 6.674391: tty_init_dev 6.675456: tty_port_link_device uart_add_one_port() registers the console, as soon as it registers, the userspace tries to use it and that leads to tty_open() but uart_add_one_port() has not yet done tty_port_link_device() and so tty->port is not yet configured when control reaches tty_init_dev(). Further look into the code and tty_port_link_device() is done by uart_add_one_port(). After registering the console uart_add_one_port() will call tty_port_register_device_attr_serdev() and tty_port_link_device() is called from this. Call add tty_port_link_device() before uart_configure_port() is done and add a check in tty_port_link_device() so that it only links the port if it has not been done yet. Suggested-by: Jiri Slaby <jslaby@suse.com> Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191212131602.29504-1-sudipm.mukherjee@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit fb2b90014d782d80d7ebf663e50f96d8c507a73c upstream.

There seems to be a race condition in tty drivers and I could see on
many boot cycles a NULL pointer dereference as tty_init_dev() tries to
do 'tty->port->itty = tty' even though tty->port is NULL.
'tty->port' will be set by the driver and if the driver has not yet done
it before we open the tty device we can get to this situation. By adding
some extra debug prints, I noticed that:

6.650130: uart_add_one_port
6.663849: register_console
6.664846: tty_open
6.674391: tty_init_dev
6.675456: tty_port_link_device

uart_add_one_port() registers the console, as soon as it registers, the
userspace tries to use it and that leads to tty_open() but
uart_add_one_port() has not yet done tty_port_link_device() and so
tty->port is not yet configured when control reaches tty_init_dev().

Further look into the code and tty_port_link_device() is done by
uart_add_one_port(). After registering the console uart_add_one_port()
will call tty_port_register_device_attr_serdev() and
tty_port_link_device() is called from this.

Call add tty_port_link_device() before uart_configure_port() is done and
add a check in tty_port_link_device() so that it only links the port if
it has not been done yet.

Suggested-by: Jiri Slaby <jslaby@suse.com>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191212131602.29504-1-sudipm.mukherjee@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
powerpc/pseries/hvconsole: Fix stack overread via udbg 2020-01-09T09:17:58+00:00 Daniel Axtens dja@axtens.net 2019-06-03T06:56:57+00:00 72e77ea7b5935428d816124fb5a104a777410d51 [ Upstream commit 934bda59f286d0221f1a3ebab7f5156a996cc37d ] While developing KASAN for 64-bit book3s, I hit the following stack over-read. It occurs because the hypercall to put characters onto the terminal takes 2 longs (128 bits/16 bytes) of characters at a time, and so hvc_put_chars() would unconditionally copy 16 bytes from the argument buffer, regardless of supplied length. However, udbg_hvc_putc() can call hvc_put_chars() with a single-byte buffer, leading to the error. ================================================================== BUG: KASAN: stack-out-of-bounds in hvc_put_chars+0xdc/0x110 Read of size 8 at addr c0000000023e7a90 by task swapper/0 CPU: 0 PID: 0 Comm: swapper Not tainted 5.2.0-rc2-next-20190528-02824-g048a6ab4835b #113 Call Trace: dump_stack+0x104/0x154 (unreliable) print_address_description+0xa0/0x30c __kasan_report+0x20c/0x224 kasan_report+0x18/0x30 __asan_report_load8_noabort+0x24/0x40 hvc_put_chars+0xdc/0x110 hvterm_raw_put_chars+0x9c/0x110 udbg_hvc_putc+0x154/0x200 udbg_write+0xf0/0x240 console_unlock+0x868/0xd30 register_console+0x970/0xe90 register_early_udbg_console+0xf8/0x114 setup_arch+0x108/0x790 start_kernel+0x104/0x784 start_here_common+0x1c/0x534 Memory state around the buggy address: c0000000023e7980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 c0000000023e7a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 >c0000000023e7a80: f1 f1 01 f2 f2 f2 00 00 00 00 00 00 00 00 00 00 ^ c0000000023e7b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 c0000000023e7b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== Document that a 16-byte buffer is requred, and provide it in udbg. Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 934bda59f286d0221f1a3ebab7f5156a996cc37d ]

While developing KASAN for 64-bit book3s, I hit the following stack
over-read.

It occurs because the hypercall to put characters onto the terminal
takes 2 longs (128 bits/16 bytes) of characters at a time, and so
hvc_put_chars() would unconditionally copy 16 bytes from the argument
buffer, regardless of supplied length. However, udbg_hvc_putc() can
call hvc_put_chars() with a single-byte buffer, leading to the error.

  ==================================================================
  BUG: KASAN: stack-out-of-bounds in hvc_put_chars+0xdc/0x110
  Read of size 8 at addr c0000000023e7a90 by task swapper/0

  CPU: 0 PID: 0 Comm: swapper Not tainted 5.2.0-rc2-next-20190528-02824-g048a6ab4835b #113
  Call Trace:
    dump_stack+0x104/0x154 (unreliable)
    print_address_description+0xa0/0x30c
    __kasan_report+0x20c/0x224
    kasan_report+0x18/0x30
    __asan_report_load8_noabort+0x24/0x40
    hvc_put_chars+0xdc/0x110
    hvterm_raw_put_chars+0x9c/0x110
    udbg_hvc_putc+0x154/0x200
    udbg_write+0xf0/0x240
    console_unlock+0x868/0xd30
    register_console+0x970/0xe90
    register_early_udbg_console+0xf8/0x114
    setup_arch+0x108/0x790
    start_kernel+0x104/0x784
    start_here_common+0x1c/0x534

  Memory state around the buggy address:
   c0000000023e7980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
   c0000000023e7a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1
  >c0000000023e7a80: f1 f1 01 f2 f2 f2 00 00 00 00 00 00 00 00 00 00
                           ^
   c0000000023e7b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
   c0000000023e7b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  ==================================================================

Document that a 16-byte buffer is requred, and provide it in udbg.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
tty: serial: msm_serial: Fix lockup for sysrq and oops 2020-01-09T09:17:58+00:00 Leo Yan leo.yan@linaro.org 2019-11-27T14:15:43+00:00 ee21b594af100be62eea7732b1f0114b2609c613 commit 0e4f7f920a5c6bfe5e851e989f27b35a0cc7fb7e upstream. As the commit 677fe555cbfb ("serial: imx: Fix recursive locking bug") has mentioned the uart driver might cause recursive locking between normal printing and the kernel debugging facilities (e.g. sysrq and oops). In the commit it gave out suggestion for fixing recursive locking issue: "The solution is to avoid locking in the sysrq case and trylock in the oops_in_progress case." This patch follows the suggestion (also used the exactly same code with other serial drivers, e.g. amba-pl011.c) to fix the recursive locking issue, this can avoid stuck caused by deadlock and print out log for sysrq and oops. Fixes: 04896a77a97b ("msm_serial: serial driver for MSM7K onboard serial peripheral.") Signed-off-by: Leo Yan <leo.yan@linaro.org> Reviewed-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com> Link: https://lore.kernel.org/r/20191127141544.4277-2-leo.yan@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 0e4f7f920a5c6bfe5e851e989f27b35a0cc7fb7e upstream.

As the commit 677fe555cbfb ("serial: imx: Fix recursive locking bug")
has mentioned the uart driver might cause recursive locking between
normal printing and the kernel debugging facilities (e.g. sysrq and
oops).  In the commit it gave out suggestion for fixing recursive
locking issue: "The solution is to avoid locking in the sysrq case
and trylock in the oops_in_progress case."

This patch follows the suggestion (also used the exactly same code with
other serial drivers, e.g. amba-pl011.c) to fix the recursive locking
issue, this can avoid stuck caused by deadlock and print out log for
sysrq and oops.

Fixes: 04896a77a97b ("msm_serial: serial driver for MSM7K onboard serial peripheral.")
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
Link: https://lore.kernel.org/r/20191127141544.4277-2-leo.yan@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty/serial: atmel: fix out of range clock divider handling 2020-01-04T13:00:09+00:00 David Engraf david.engraf@sysgo.com 2019-12-16T08:54:03+00:00 52a6ba0b4a6efb04557c64e5c90bcd1b97c1238e [ Upstream commit cb47b9f8630ae3fa3f5fbd0c7003faba7abdf711 ] Use MCK_DIV8 when the clock divider is > 65535. Unfortunately the mode register was already written thus the clock selection is ignored. Fix by doing the baud rate calulation before setting the mode. Fixes: 5bf5635ac170 ("tty/serial: atmel: add fractional baud rate support") Signed-off-by: David Engraf <david.engraf@sysgo.com> Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com> Acked-by: Richard Genoud <richard.genoud@gmail.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191216085403.17050-1-david.engraf@sysgo.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit cb47b9f8630ae3fa3f5fbd0c7003faba7abdf711 ]

Use MCK_DIV8 when the clock divider is > 65535. Unfortunately the mode
register was already written thus the clock selection is ignored.

Fix by doing the baud rate calulation before setting the mode.

Fixes: 5bf5635ac170 ("tty/serial: atmel: add fractional baud rate support")
Signed-off-by: David Engraf <david.engraf@sysgo.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191216085403.17050-1-david.engraf@sysgo.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
tty: vt: keyboard: reject invalid keycodes 2019-12-17T19:38:49+00:00 Dmitry Torokhov dmitry.torokhov@gmail.com 2019-11-22T20:42:20+00:00 c68ab0f33eabef9c9d4206cec2fb6509d1d5b621 commit b2b2dd71e0859436d4e05b2f61f86140250ed3f8 upstream. Do not try to handle keycodes that are too big, otherwise we risk doing out-of-bounds writes: BUG: KASAN: global-out-of-bounds in clear_bit include/asm-generic/bitops-instrumented.h:56 [inline] BUG: KASAN: global-out-of-bounds in kbd_keycode drivers/tty/vt/keyboard.c:1411 [inline] BUG: KASAN: global-out-of-bounds in kbd_event+0xe6b/0x3790 drivers/tty/vt/keyboard.c:1495 Write of size 8 at addr ffffffff89a1b2d8 by task syz-executor108/1722 ... kbd_keycode drivers/tty/vt/keyboard.c:1411 [inline] kbd_event+0xe6b/0x3790 drivers/tty/vt/keyboard.c:1495 input_to_handler+0x3b6/0x4c0 drivers/input/input.c:118 input_pass_values.part.0+0x2e3/0x720 drivers/input/input.c:145 input_pass_values drivers/input/input.c:949 [inline] input_set_keycode+0x290/0x320 drivers/input/input.c:954 evdev_handle_set_keycode_v2+0xc4/0x120 drivers/input/evdev.c:882 evdev_do_ioctl drivers/input/evdev.c:1150 [inline] In this case we were dealing with a fuzzed HID device that declared over 12K buttons, and while HID layer should not be reporting to us such big keycodes, we should also be defensive and reject invalid data ourselves as well. Reported-by: syzbot+19340dff067c2d3835c0@syzkaller.appspotmail.com Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191122204220.GA129459@dtor-ws Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit b2b2dd71e0859436d4e05b2f61f86140250ed3f8 upstream.

Do not try to handle keycodes that are too big, otherwise we risk doing
out-of-bounds writes:

BUG: KASAN: global-out-of-bounds in clear_bit include/asm-generic/bitops-instrumented.h:56 [inline]
BUG: KASAN: global-out-of-bounds in kbd_keycode drivers/tty/vt/keyboard.c:1411 [inline]
BUG: KASAN: global-out-of-bounds in kbd_event+0xe6b/0x3790 drivers/tty/vt/keyboard.c:1495
Write of size 8 at addr ffffffff89a1b2d8 by task syz-executor108/1722
...
 kbd_keycode drivers/tty/vt/keyboard.c:1411 [inline]
 kbd_event+0xe6b/0x3790 drivers/tty/vt/keyboard.c:1495
 input_to_handler+0x3b6/0x4c0 drivers/input/input.c:118
 input_pass_values.part.0+0x2e3/0x720 drivers/input/input.c:145
 input_pass_values drivers/input/input.c:949 [inline]
 input_set_keycode+0x290/0x320 drivers/input/input.c:954
 evdev_handle_set_keycode_v2+0xc4/0x120 drivers/input/evdev.c:882
 evdev_do_ioctl drivers/input/evdev.c:1150 [inline]

In this case we were dealing with a fuzzed HID device that declared over
12K buttons, and while HID layer should not be reporting to us such big
keycodes, we should also be defensive and reject invalid data ourselves as
well.

Reported-by: syzbot+19340dff067c2d3835c0@syzkaller.appspotmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191122204220.GA129459@dtor-ws
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: Don't block on IO when ldisc change is pending 2019-12-17T19:38:37+00:00 Dmitry Safonov dima@arista.com 2018-11-01T00:24:48+00:00 ebded7823e7f1aedf9d8b47a5cb006119895a9d2 [ Upstream commit c96cf923a98d1b094df9f0cf97a83e118817e31b ] There might be situations where tty_ldisc_lock() has blocked, but there is already IO on tty and it prevents line discipline changes. It might theoretically turn into dead-lock. Basically, provide more priority to pending tty_ldisc_lock() than to servicing reads/writes over tty. User-visible issue was reported by Mikulas where on pa-risc with Debian 5 reboot took either 80 seconds, 3 minutes or 3:25 after proper locking in tty_reopen(). Cc: Jiri Slaby <jslaby@suse.com> Reported-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit c96cf923a98d1b094df9f0cf97a83e118817e31b ]

There might be situations where tty_ldisc_lock() has blocked, but there
is already IO on tty and it prevents line discipline changes.
It might theoretically turn into dead-lock.

Basically, provide more priority to pending tty_ldisc_lock() than to
servicing reads/writes over tty.

User-visible issue was reported by Mikulas where on pa-risc with
Debian 5 reboot took either 80 seconds, 3 minutes or 3:25 after proper
locking in tty_reopen().

Cc: Jiri Slaby <jslaby@suse.com>
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
serial: imx: fix error handling in console_setup 2019-12-17T19:38:14+00:00 Stefan Agner stefan@agner.ch 2018-11-14T17:49:38+00:00 b287fd473e054a9d0cbc625ca96343e870a61a5e [ Upstream commit 63fd4b94b948c14eeb27a3bbf50ea0f7f0593bad ] The ipg clock only needs to be unprepared in case preparing per clock fails. The ipg clock has already disabled at the point. Fixes: 1cf93e0d5488 ("serial: imx: remove the uart_console() check") Signed-off-by: Stefan Agner <stefan@agner.ch> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 63fd4b94b948c14eeb27a3bbf50ea0f7f0593bad ]

The ipg clock only needs to be unprepared in case preparing
per clock fails. The ipg clock has already disabled at the point.

Fixes: 1cf93e0d5488 ("serial: imx: remove the uart_console() check")
Signed-off-by: Stefan Agner <stefan@agner.ch>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>