Linux mainline fork with MSM8998 patches | https://mainline.space | Currently supported devices: OnePlus 5/5T, Xiaomi Mi 6, F(x)tec Pro¹ (2019 QX1000 model) & Sony Xperia XZ Premium (UNTESTED!)
Find a file
Joel Stanley d46fddd52d fsi: scom: Fix error handling
SCOM error handling is made complex by trying to pass around two bits of
information: the function return code, and a status parameter that
represents the CFAM error status register.

The commit f72ddbe1d7 ("fsi: scom: Remove retries") removed the
"hidden" retries in the SCOM driver, in preference of allowing the
calling code (userspace or driver) to decide how to handle a failed
SCOM. However it introduced a bug by attempting to be smart about the
return codes that were "errors" and which were ok to fall through to the
status register parsing.

We get the following errors:

 - EINVAL or ENXIO, for indirect scoms where the value is invalid
 - EINVAL, where the size or address is incorrect
 - EIO or ETIMEOUT, where FSI write failed (aspeed master)
 - EAGAIN, where the master detected a crc error (GPIO master only)
 - EBUSY, where the bus is disabled (GPIO master in external mode)

In all of these cases we should fail the SCOM read/write and return the
error.

Thanks to Dan Carpenter for the detailed bug report.

Fixes: f72ddbe1d7 ("fsi: scom: Remove retries")
Link: https://lists.ozlabs.org/pipermail/linux-fsi/2021-November/000235.html
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20211207033811.518981-2-joel@jms.id.au
Signed-off-by: Joel Stanley <joel@jms.id.au>
2022-01-31 15:56:55 +10:30
arch
block
certs
crypto
Documentation
drivers fsi: scom: Fix error handling 2022-01-31 15:56:55 +10:30
fs
include
init
ipc
kernel ftrace: Fix s390 breakage from sorting mcount tables 2022-01-23 08:07:02 +02:00
lib
LICENSES
mm
net
samples
scripts
security
sound
tools perf tools changes for v5.17: 2nd batch 2022-01-23 08:14:21 +02:00
usr
virt
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS
Makefile Linux 5.17-rc1 2022-01-23 10:12:53 +02:00
README

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.