Clean up our struct a little bit by using a union instead of
a struct for tracking the subtype of a device.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If we fail to find the input / output port for a LINK component
while enabling a path, we should fail gracefully rather than
assuming port "0".
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We request for "CORESIGHT_BARRIER_PKT_SIZE" length and we should
be happy when we get that size.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The newly introduced code fails to build in some configurations
unless we include the right headers:
drivers/hwtracing/coresight/coresight-tmc-etr.c: In function 'tmc_free_table_pages':
drivers/hwtracing/coresight/coresight-tmc-etr.c:206:3: error: implicit declaration of function 'vunmap'; did you mean 'iounmap'? [-Werror=implicit-function-declaration]
Fixes: 79613ae8715a ("coresight: Add generic TMC sg table framework")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that we can dynamically switch between contiguous memory and
SG table depending on the trace buffer size, provide the support
for selecting an appropriate buffer size.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add the support for Scatter-Gather mode to the etr-buf layer.
Since we now have two different modes, we choose the backend
based on a set of conditions, documented in the code.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The TMC-ETR can use the target trace buffer in two different modes.
Normal physically contiguous mode and a discontiguous list pages in
Scatter-Gather mode. Also we have dedicated Coresight component, CATU
(Coresight Address Translation Unit) to provide improved scatter-gather
mode in Coresight SoC-600. This complicates the management of the
buffer used for trace, depending on the mode in which ETR is configured.
So, this patch adds a transparent layer for managing the ETR buffer
which abstracts the basic operations on the buffer (alloc, free,
sync and retrieve the data) and uses the mode specific helpers to
do the actual operation. This also allows the ETR driver to choose
the best mode for a given use case and adds the flexibility to
fallback to a different mode, without duplicating the code.
The patch also adds the "normal" flat memory mode and switches
the sysfs driver to use the new layer.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds support for setting up an SG table used by the
TMC ETR inbuilt SG unit. The TMC ETR uses 4K page sized tables
to hold pointers to the 4K data pages with the last entry in a
table pointing to the next table with the entries, by kind of
chaining. The 2 LSBs determine the type of the table entry, to
one of :
Normal - Points to a 4KB data page.
Last - Points to a 4KB data page, but is the last entry in the
page table.
Link - Points to another 4KB table page with pointers to data.
The code takes care of handling the system page size which could
be different than 4K. So we could end up putting multiple ETR
SG tables in a single system page, vice versa for the data pages.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch introduces a generic sg table data structure and
associated operations. An SG table can be used to map a set
of Data pages where the trace data could be stored by the TMC
ETR. The information about the data pages could be stored in
different formats, depending on the type of the underlying
SG mechanism (e.g, TMC ETR SG vs Coresight CATU). The generic
structure provides book keeping of the pages used for the data
as well as the table contents. The table should be filled by
the user of the infrastructure.
A table can be created by specifying the number of data pages
as well as the number of table pages required to hold the
pointers, where the latter could be different for different
types of tables. The pages are mapped in the appropriate dma
data direction mode (i.e, DMA_TO_DEVICE for table pages
and DMA_FROM_DEVICE for data pages). The framework can optionally
accept a set of allocated data pages (e.g, perf ring buffer) and
map them accordingly. The table and data pages are vmap'ed to allow
easier access by the drivers. The framework also provides helpers to
sync the data written to the pages with appropriate directions.
This will be later used by the TMC ETR SG unit and CATU.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We are about to add the support for ETR builtin scatter-gather mode
for dealing with large amount of trace buffers. However, on some of
the platforms, using the ETR SG mode can lock up the system due to
the way the ETR is connected to the memory subsystem.
In SG mode, the ETR performs READ from the scatter-gather table to
fetch the next page and regular WRITE of trace data. If the READ
operation doesn't complete(due to the memory subsystem issues,
which we have seen on a couple of platforms) the trace WRITE
cannot proceed leading to issues. So, we by default do not
use the SG mode, unless it is known to be safe on the platform.
We define a DT property for the TMC node to specify whether we
have a proper SG mode.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: John Horley <john.horley@arm.com>
Cc: Robert Walker <robert.walker@arm.com>
Cc: devicetree@vger.kernel.org
Cc: frowand.list@gmail.com
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Right now we open code filling the trace buffer with synchronization
packets when the circular buffer wraps around in different drivers.
Move this to a common place. While at it, clean up the barrier_pkt
array to strip off the trailing '\0'.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We don't support ETR in perf mode yet. So, don't
even try to enable the hardware, even by mistake.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We zero out the entire trace buffer used for ETR before it is enabled,
for helping with debugging. With the addition of scatter-gather mode,
the buffer could be bigger and non-contiguous.
Get rid of this step; if someone wants to debug, they can always add it
as and when needed.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
At the moment we adjust the buffer pointers for reading the trace
data via misc device in the common code for ETF/ETB and ETR. Since
we are going to change how we manage the buffer for ETR, let us
move the buffer manipulation to the respective driver files, hiding
it from the common code. We do so by adding type specific helpers
for finding the length of data and the pointer to the buffer,
for a given length at a file position.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add ETM PIDs of the Arm cortex-A CPUs to the white list of ETMs.
While at it add a helper macro to make it easier to add the new
entries.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that we prevent users from using contextID tracing when PID namespaces
are involved there is no client for function coresight_vpid_to_pid(). As
such simply remove it.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Kim Phillips <kim.phillips@arm.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As with ETM3x, the ETM4x tracers can trigger trace acquisition based on
contextID value, something that isn't useful when PID namespaces are
enabled. Indeed the PID value of a process has a different representation
in the kernel and the PID namespace, making the feature confusing and
potentially leaking internal kernel information.
As such simply return an error when the feature is being used from a
PID namespace other than the default one.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Kim Phillips <kim.phillips@arm.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tracers can trigger trace acquisition based on contextID value, something
that isn't useful when PID namespaces are enabled. Indeed the PID value
of a process has a different representation in the kernel and the PID
namespace, making the feature confusing and potentially leaking internal
kernel information.
As such simply return an error when the feature is being used from a
PID namespace other than the default one.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Kim Phillips <kim.phillips@arm.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use ssize_t for rets variables in mei_write(), mei_read(), and
mei_cl_write() as well as change the return type of mei_cl_write()
to ssize_t, to prevent assignment of possible 64bit size_t
to int 32 bit variable.
As by product also eliminate warning
drivers/misc/mei/client.c:1702:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In for loops use same type for counter variable
as has the limiting variable.
drivers/misc/mei/bus-fixup.c:489:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
drivers/misc/mei/hw-txe.c:725:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
drivers/misc/mei/hw-txe.c:744:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mei_hbuf_empty_slots() may return with an error in case
of circular buffer overflow. This type of error may
be caused only by a bug. However currently, the error
won't be detected due signed type promotion in comparison to u32.
We add explicit check for less then zero and explicit cast
in comparison to suppress singn-compare warning.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
MEI enables writes of complete messages only
while read can be performed in parts, hence
write should not update the file offset to
not break interleaving partial reads with writes.
Cc: <stable@vger.kernel.org>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
if __mei_cl_recv() returns a negative then "bytes_recv"
type is promoted to a high positive value in comparison with
size_t evaluated by MKHI_FWVER_LEN(1). It results in error condition
not to be detected.
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 9078ad92ef86 ("mei: expose fw version to sysfs")
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We accidentally removed the check for negative returns
without considering the issue of type promotion.
The "if_version_length" variable is type size_t so if __mei_cl_recv()
returns a negative then "bytes_recv" is type promoted
to a high positive value and treated as success.
Cc: <stable@vger.kernel.org>
Fixes: 582ab27a06 ("mei: bus: fix received data size check in NFC fixup")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This moves the definitions for various protocol details
(message & response codes, delays etc...) out of
fsi-master-gpio.c to fsi-master.h in order to share them
with other master implementations.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
The embedded struct device needs a release function to be
able to successfully remove the driver.
We remove the devm_gpiod_put() as they are unnecessary
(the resources will be released automatically) and because
fsi_master_unregister() will cause the master structure to
be freed.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
In the error path of fsi_master_register(), we currently
use device_unregister(). This will cause the last reference
to the structure to be dropped, thus freeing the enclosing
structure, which isn't what the callers want.
Use device_del() instead so that we return to the caller
with a refcount of 1. The caller can then assume that it
must use put_device() after a call to fsi_master_register()
regardless of whether the latter suceeded or failed.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Some definitions are generic to the FSI protocol or any
give master implementation. Rename them to remove the
"GPIO" prefix in preparation for moving them to a common
header.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
# Conflicts:
# drivers/fsi/fsi-master-gpio.c
This adds a few more tracepoints that have proven useful when
debugging issues with the FSI bus.
This also makes echo_delay() use clock_zeros() instead of
open-code it in order to share the tracepoint.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
What the driver called "FSI_GPIO_PRIME_SLAVE_CLOCKS" is what
the FSI spec calls tSendDelay and should be 16 clocks by
default.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Those values control the amount of "dummy" clocks between commands and
between a command and its response.
This adds a way to configure them from sysfs (to be later extended to
defaults in the device-tree). The default remains 16 (the HW default).
This is only supported if the backend supports the new link_config()
callback to configure the generation of those delays.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
---
Move fsi_slave_set_smode() and its helpers to before it's
first user and remove the corresponding forward declaration.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
"dev" is dereferences before it's checked.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The driver calls of_platform_device_create() which is only available
if OF_ADDRESS is enabled. When building sparc64 images, this results
in
ERROR: "of_platform_device_create" [drivers/fsi/fsi-sbefifo.ko] undefined!
Fixes: 9f4a8a2d7f ("fsi/sbefifo: Add driver for the SBE FIFO")
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
There was no unlock of the FFDC mutex.
Fixes: 9f4a8a2d7f ("fsi/sbefifo: Add driver for the SBE FIFO")
Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Another driver turned up that is missing linux/mod_devicetable.h after
the device IDs are split out from linux/platform_device.h:
drivers/extcon/extcon-max3355.c:127:34: error: array type has incomplete element type 'struct of_device_id'
static const struct of_device_id max3355_match_table[] = {
Fixes: ac3167257b ("headers: separate linux/mod_devicetable.h from linux/platform_device.h")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A couple of drivers produced build errors after the mod_devicetable.h
header was split out from the platform_device one, e.g.
drivers/media/platform/davinci/vpbe_osd.c:42:40: error: array type has incomplete element type 'struct platform_device_id'
drivers/media/platform/davinci/vpbe_venc.c:42:40: error: array type has incomplete element type 'struct platform_device_id'
This adds the inclusion where needed.
Fixes: ac3167257b ("headers: separate linux/mod_devicetable.h from linux/platform_device.h")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the VM mode on Hyper-V, currently, when the kernel panics, an error
code and few register values are populated in an MSR and the Hypervisor
notified. This information is collected on the host. The amount of
information currently collected is found to be limited and not very
actionable. To gather more actionable data, such as stack trace, the
proposal is to write one page worth of kmsg data on an allocated page
and the Hypervisor notified of the page address through the MSR.
- Sysctl option to control the behavior, with ON by default.
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes below warning during building htmldoc:
slimbus.h:352: warning: Function parameter or member 'name'
not described in 'slim_stream_runtime'
This patch also removes documentation for state variable
in struct slim_stream_runtime which was redundant and removed.
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/arm/plat-samsung/adc.c needs to #include <linux/mod_devicetable.h>
explicitly since that header file was removed from
<linux/platform_device.h> (it wasn't needed there).
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
At over 4000 #includes, <linux/platform_device.h> is the 9th most
#included header file in the Linux kernel. It does not need
<linux/mod_devicetable.h>, so drop that header and explicitly add
<linux/mod_devicetable.h> to source files that need it.
4146 #include <linux/platform_device.h>
After this patch, there are 225 files that use <linux/mod_devicetable.h>,
for a reduction of around 3900 times that <linux/mod_devicetable.h>
does not have to be read & parsed.
225 #include <linux/mod_devicetable.h>
This patch was build-tested on 20 different arch-es.
It also makes these drivers SubmitChecklist#1 compliant.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kbuild test robot <lkp@intel.com> # drivers/media/platform/vimc/
Reported-by: kbuild test robot <lkp@intel.com> # drivers/pinctrl/pinctrl-u300.c
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The GPIO subsystem provides dummy GPIO consumer functions if GPIOLIB is
not enabled. Hence drivers that depend on GPIOLIB, but use GPIO consumer
functionality only, can still be compiled if GPIOLIB is not enabled.
Relax the dependency on GPIOLIB if COMPILE_TEST is enabled, where
appropriate.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As of commit 7124330dab ("m68k/uaccess: Revive 64-bit
get_user()"), the 64-bit Android binder interface builds fine on m68k.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Checking whether output of commands matches the ver_linux pattern in
the version function is original shell implementation legacy code. When
the original implementation failed to locate a particular utility,
it generated error output along the lines of:
ver_linux:line number: command not found.
The awk implementation, does not contain the name of the script within the
body of the error message returned by the subshell when a given utility
fails to be located. The error message returned is along the lines of:
sh: name of utility: command not found
Safeguarding against the ver_linux pattern being found in the output
being parsed may thus be safely omitted.
Signed-off-by: Alexander Kapshuk <alexander.kapshuk@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, input coming from /proc/self/maps is split into fields without
checking whether or not it matches libc.so. This is not efficient.
All text processing should only be performed on lines of input that
match libc.so.
Signed-off-by: Alexander Kapshuk <alexander.kapshuk@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ADC channel 0 photodiode detects both infrared + visible light,
but ADC channel 1 just detects infrared. However, the latter is a bit
more sensitive in that range so complete darkness or low light causes
a error condition in which the chan0 - chan1 is negative that
results in a -EAGAIN.
This patch changes the resulting lux1_input sysfs attribute message from
"Resource temporarily unavailable" to a user-grokable lux value of 0.
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
