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Stephan Gerhold 8f4a7a00c1 arm64: dts: qcom: msm8916-samsung-a2015: Reserve Samsung firmware memory
At the moment, writing large amounts of data to the eMMC causes the device
to freeze. The symptoms vary, sometimes the device reboots immediately,
but usually it will just get stuck.

It turns out that the issue is not actually related to the eMMC:
Apparently, Samsung has made some modifications to the TrustZone firmware.
These require additional memory which is reserved at 0x85500000-0x86000000.
The downstream kernel describes this memory reservation as:

/* Additionally Reserved 6MB for TIMA and Increased the TZ app size
 * by 2MB [total 8 MB ]
 */

This suggests that it is used for additional TZ apps, although the extra
memory is actually 11 MB instead of the 8 MB mentioned in the comment.

Writing to the protected memory causes the kernel to crash or freeze.
In our case, writing to the eMMC causes the disk cache to fill
the available RAM, until the kernel eventually crashes
when attempting to use the reserved memory.

Add the additional memory as reserved-memory to fix this problem.

Fixes: 1329c1ab07 ("arm64: dts: qcom: Add device tree for Samsung Galaxy A3U/A5U")
Reported-by: Michael Srba <Michael.Srba@seznam.cz>
Tested-by: Michael Srba <Michael.Srba@seznam.cz> # a3u
Tested-by: Stephan Gerhold <stephan@gerhold.net> # a5u
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20191231112511.83342-1-stephan@gerhold.net
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
2020-02-11 22:21:07 -08:00
arch arm64: dts: qcom: msm8916-samsung-a2015: Reserve Samsung firmware memory 2020-02-11 22:21:07 -08:00
block block-5.6-2020-02-05 2020-02-06 06:15:23 +00:00
certs certs: Add wrapper function to check blacklisted binary hash 2019-11-12 12:25:50 +11:00
crypto treewide: remove redundant IS_ERR() before error code check 2020-02-04 03:05:27 +00:00
Documentation Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
drivers Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
fs Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
include fs: New zonefs file system 2020-02-09 15:51:46 -08:00
init Tracing updates: 2020-02-06 07:12:11 +00:00
ipc proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
kernel Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
lib Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm Merge branch 'merge.nfs-fs_parse.1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-02-08 13:26:41 -08:00
net Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
samples Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
scripts Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
security Merge branch 'merge.nfs-fs_parse.1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-02-08 13:26:41 -08:00
sound sound fixes for 5.6-rc1 2020-02-06 14:15:01 +00:00
tools A set of fixes and improvements for the perf subsystem: 2020-02-09 12:04:09 -08:00
usr Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
virt KVM: fix overflow of zero page refcount with ksm running 2020-02-05 15:27:46 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore modpost: dump missing namespaces into a single modules.nsdeps file 2019-11-11 20:10:01 +09:00
.mailmap A handful of small documentation fixes that wandered in. 2020-02-07 13:03:10 -08:00
COPYING
CREDITS open: introduce openat2(2) syscall 2020-01-18 09:19:18 -05:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS fs: New zonefs file system 2020-02-09 15:51:46 -08:00
Makefile Linux 5.6-rc1 2020-02-09 16:08:48 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.