Marek Szyprowski a6f483b2e4 spi: Fix potential NULL pointer dereference in spi_shutdown()
Shutdown bus function might be called on the unbound device, so add a
check if there is a driver before calling its shutdown function.

This fixes following kernel panic obserbed during system reboot:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000018
...
Call trace:
 spi_shutdown+0x10/0x38
 kernel_restart_prepare+0x34/0x40
 kernel_restart+0x14/0x88
 __do_sys_reboot+0x148/0x248
 __arm64_sys_reboot+0x1c/0x28
 el0_svc_common.constprop.3+0x74/0x198
 do_el0_svc+0x20/0x98
 el0_sync_handler+0x140/0x1a8
 el0_sync+0x140/0x180
Code: f9403402 d1008041 f100005f 9a9f1021 (f9400c21)
---[ end trace 266c07205a2d632e ]---

Fixes: 9db34ee64c (spi: Use bus_type functions for probe, remove and shutdown)
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20201124131523.32287-1-m.szyprowski@samsung.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-11-24 14:14:39 +00:00
2020-10-25 15:14:11 -07:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Description
No description provided
Readme 3.4 GiB
Languages
C 97%
Assembly 1%
Shell 0.6%
Rust 0.5%
Python 0.4%
Other 0.3%