Remove the compile-time option for FAST_READ, since we have run-time
support for detecting it. This refactors the logic for enabling
fast-read, such that for DT-enabled devices, we honor the
"m25p,fast-read" property but for non-DT devices, we default to using
FAST_READ whenever the flash device supports it.
Normal READ and FAST_READ differ only in the following:
* FAST_READ supports SPI higher clock frequencies [1]
* number of dummy cycles; FAST_READ requires 8 dummy cycles (whereas
READ requires 0) to allow the flash sufficient setup time, even when
running at higher clock speeds
Thus, for flash chips which support FAST_READ, there is otherwise no
limiting reason why we cannot use the FAST_READ opcode instead of READ.
It simply allows the SPI controller to run at higher clock rates. So
theoretically, nobody should be needing the compile-time option anyway.
[1] I have a Spansion S25FL128S datasheet which says:
"The maximum operating clock frequency for the READ command is 50
MHz."
And:
"The maximum operating clock frequency for FAST READ command is 133
MHz."
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
The FIXME and NOTE have already been fixed (we have FAST_READ support).
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Sourav Poddar <sourav.poddar@ti.com>
Acked-by: Marek Vasut <marex@denx.de>
This patch fixes two memory errors:
1. During a probe failure (in mtd_device_parse_register?) the command
buffer would not be freed.
2. The command buffer's size is determined based on the 'fast_read'
boolean, but the assignment of fast_read is made after this
allocation. Thus, the buffer may be allocated "too small".
To fix the first, just switch to the devres version of kzalloc.
To fix the second, increase MAX_CMD_SIZE unconditionally. It's not worth
saving a byte to fiddle around with the conditions here.
This problem was reported by Yuhang Wang a while back.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reported-by: Yuhang Wang <wangyuhang2014@gmail.com>
Reviewed-by: Sourav Poddar <sourav.poddar@ti.com>
Cc: <stable@vger.kernel.org>
In the imx6, all the ready/busy pins are binding togeter.
So we should always check the ready/busy pin of the chip 0.
In the other word, when the CS1 is enabled, we should also check the
ready/busy of chip 0; if we check the ready/busy of chip 1,
we will get the wrong result.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Some nand chip has two DIEs in a single chip, such as Micron MT29F32G08QAA.
Each die has its own chip select pin, so this chip acts as two nand
chips.
If we only scan one chip, we may find that we only get 2G for this chip,
but in actually, this chip's size is 4G.
So scan two chips by default.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
We only have one DMA channel : the channel 0.
Use DMA channel 0 to access all the nand chips.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Decouple the chip select from the DMA channel, we use the DMA channel 0
to accecc all the nand devices.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
as per controller description,
"While programming a NAND flash, status read should never skipped.
Because it may happen that a new command is issued to the NAND Flash,
even when the device has not yet finished processing the previous request.
This may result in unpredictable behaviour."
IFC controller never polls for R/B signal after command send. It just return
control to software. This behaviour may not occur with NAND flash access.
because new commands are sent after polling R/B signal. But it may happen
in scenario where GPCM-ASIC and NAND flash device are working simultaneously.
Update the controller driver to take care of this requirement
Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Current IFC driver supports till 4K page size NAND flash.
Add support of 8K Page size NAND flash
- Add nand_ecclayout for 4 bit & 8 bit ecc
- Defines constants
- also fix ecc.strength for 8bit ecc of 8K page size NAND
Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Hardware:
CPU: XLP832,the 64-bit OS
NOR Flash:S29GL128S 128M
Software:
Kernel:2.6.32.41
Filesystem:JFFS2
When writing files, errors appear:
Write len 182 but return retlen 180
Write of 182 bytes at 0x072c815c failed. returned -5, retlen 180
Write len 186 but return retlen 184
Write of 186 bytes at 0x072caff4 failed. returned -5, retlen 184
These errors exist only in 64-bit systems,not in 32-bit systems. After analysis, we
found that the left shift operation is wrong in map_word_load_partial. For instance:
unsigned char buf[3] ={0x9e,0x3a,0xea};
map_bankwidth(map) is 4;
for (i=0; i < 3; i++) {
int bitpos;
bitpos = (map_bankwidth(map)-1-i)*8;
orig.x[0] &= ~(0xff << bitpos);
orig.x[0] |= buf[i] << bitpos;
}
The value of orig.x[0] is expected to be 0x9e3aeaff, but in this situation(64-bit
System) we'll get the wrong value of 0xffffffff9e3aeaff due to the 64-bit sign
extension:
buf[i] is defined as "unsigned char" and the left-shift operation will convert it
to the type of "signed int", so when left-shift buf[i] by 24 bits, the final result
will get the wrong value: 0xffffffff9e3aeaff.
If the left-shift bits are less than 24, then sign extension will not occur. Whereas
the bankwidth of the nor flash we used is 4, therefore this BUG emerges.
Signed-off-by: Pang Xunlei <pang.xunlei@zte.com.cn>
Signed-off-by: Zhang Yi <zhang.yi20@zte.com.cn>
Signed-off-by: Lu Zhongjun <lu.zhongjun@zte.com.cn>
Cc: <stable@vger.kernel.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
This patch moves the char and block major number definitions
to major.h to be with the rest of the major numbers.
While doing this, include major.h in the files that need it.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
A new type of partition with magic FCTY was found on Huawei E970:
46 43 54 59 4b 51 37 4e 41 42 31 38 41 32 39 30 |FCTYKQ7NAB18A290|
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Most of the bcm47xx devices use TRX format for storing kernel and some
partition like Squashfs or JFFS2. This is pretty flexible solution, CFE
(the bootloader) just writes (and later boots) TRX at some hardcoded
place and paritions can vary in the size.
However some devices don't use TRX format. Very recently we have
discovered ZTE H218N that has kernel and rootfs partitions at some
"random" places.
This patch allows Linux find a rootfs partition after installing custom
image with a CFE bootloader.
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
devm_kzalloc is device managed and simplifies the code.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Some bright specification writers decided to write this in the ONFI spec
(from ONFI 3.0, Section 3.1):
"The number of blocks and number of pages per block is not required to
be a power of two. In the case where one of these values is not a
power of two, the corresponding address shall be rounded to an
integral number of bits such that it addresses a range up to the
subsequent power of two value. The host shall not access upper
addresses in a range that is shown as not supported."
This breaks every assumption MTD makes about NAND block/chip-size
dimensions -- they *must* be a power of two!
And of course, an enterprising manufacturer has made use of this lovely
freedom. Exhibit A: Micron MT29F32G08CBADAWP
"- Plane size: 2 planes x 1064 blocks per plane
- Device size: 32Gb: 2128 blockss [sic]"
This quickly hits a BUG() in nand_base.c, since the extra dimensions
overflow so we think it's a second chip (on my single-chip setup):
ONFI param page 0 valid
ONFI flash detected
NAND device: Manufacturer ID: 0x2c, Chip ID: 0x44 (Micron MT29F32G08CBADAWP), 4256MiB, page size: 8192, OOB size: 744
------------[ cut here ]------------
kernel BUG at drivers/mtd/nand/nand_base.c:203!
Internal error: Oops - BUG: 0 [#1] SMP ARM
[... trim ...]
[<c02cf3e4>] (nand_select_chip+0x18/0x2c) from [<c02d25c0>] (nand_do_read_ops+0x90/0x424)
[<c02d25c0>] (nand_do_read_ops+0x90/0x424) from [<c02d2dd8>] (nand_read+0x54/0x78)
[<c02d2dd8>] (nand_read+0x54/0x78) from [<c02ad2c8>] (mtd_read+0x84/0xbc)
[<c02ad2c8>] (mtd_read+0x84/0xbc) from [<c02d4b28>] (scan_read.clone.4+0x4c/0x64)
[<c02d4b28>] (scan_read.clone.4+0x4c/0x64) from [<c02d4c88>] (search_bbt+0x148/0x290)
[<c02d4c88>] (search_bbt+0x148/0x290) from [<c02d4ea4>] (nand_scan_bbt+0xd4/0x5c0)
[... trim ...]
---[ end trace 0c9363860d865ff2 ]---
So to fix this, just truncate these dimensions down to the greatest
power-of-2 dimension that is less than or equal to the specified
dimension.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: <stable@vger.kernel.org>
This commit replaces the currently hardcoded buffer size, by a
dynamic detection scheme. First a small 256 bytes buffer is allocated
so the device can be detected (using READID and friends commands).
After detection, this buffer is released and a new buffer is allocated
to acommodate the page size plus out-of-band size.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Instead of setting info->dma each time a command is prepared,
we can move it after the DMA buffers are allocated.
This is more clear and it's the proper place to enable this, given
DMA cannot be turned on and off during runtime.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Micron N25Q512A is a spi flash memory with following features:
-64MB size, 1.8V, Mulitple I/O, 4KB Sector erase memory.
-Memory is organised as 1024(64KB) main sectors.
-Each sector is divided into 256 pages.
-Register set/Opcodes are similar to other N25Q family products.
Signed-off-by: Priyanka Jain <Priyanka.Jain@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Use free_bch() instead of kfree() to free init_bch()
allocated data.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
The loop that polls the status register waiting for an operation to complete
foolishly bases the timeout simply on the number of loop iterations that have
ocurred. When I increased the processor clock speed, timeouts started to appear
for long block erasure operations. This patch measures the timeout using
jiffies.
Signed-off-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
devm_kzalloc is device managed and makes code simpler.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Driver core will set the driver data to NULL upon detach or
probe failure.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
module_platform_driver removes boiler plate code and makes it
simpler.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Driver core will set the driver data to NULL upon detach or
probe failure.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
devm_kzalloc is device managed and makes code simpler.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Driver core will set the driver data to NULL upon detach
or probe failure.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
The data structure of_match_ptr() protects is always compiled in.
Hence of_match_ptr() is not needed.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
The data structure of_match_ptr() protects is always compiled in.
Hence of_match_ptr() is not needed.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
The data structure of_match_ptr() protects is always compiled in.
Hence of_match_ptr() is not needed.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
phram was 32-bit limited by design. Machines are growing up, but phram
module is still useful. Update it. The patch is bigger than minimum,
because simple_strtoul() is obsolete.
Tested on MIPS64 and compile-tested for PPC (32 bit).
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nsn.com>
Reviewed-by: Joern Engel <joern@logfs.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Just an unnecessary semicolon that should be removed...
Whitespace neatening of macro too.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use a more standard logging style.
Convert smsc_<level> macros to use netif_<level>.
Remove unused #define PFX
Add pr_fmt and neaten pr_<level> uses.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
BIOS on ASUS W5A laptop with ALC880 codec doesn't provide any pin
configurations, so we have to set up all pins manually.
Reported-and-tested-by: nb <nb@dagami.org>
Cc: <stable@vger.kernel.org> [v3.4+]
Signed-off-by: Takashi Iwai <tiwai@suse.de>
It's a superset of the existing CX2075x codecs, so we can reuse the
existing parser code.
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Here's the big drivers/staging/ update for 3.13-rc1.
Nothing major here, just a _ton_ of fixes and cleanups, mostly driven by
the new round of OPW applicants, but also there are lots of other people
doing staging tree cleanups these days in order to help get the drivers
into mergable shape.
We also merge, and then revert, the ktap code, as Ingo and the other
perf/ftrace developers feel it should go into the "real" part of the
kernel with only a bit more work, so no need to put it in staging for
now.
All of this has been in linux-next for a while with no reported issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.19 (GNU/Linux)
iEYEABECAAYFAlJ6xPsACgkQMUfUDdst+ykAbwCg1hOktgHPFZp/t6xmsSj6cZHj
AfQAnRN/lr/TFw5SKUek2sluAzO4Fz7c
=g/MD
-----END PGP SIGNATURE-----
Merge tag 'staging-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging driver update from Greg KH:
"Here's the big drivers/staging/ update for 3.13-rc1.
Nothing major here, just a _ton_ of fixes and cleanups, mostly driven
by the new round of OPW applicants, but also there are lots of other
people doing staging tree cleanups these days in order to help get the
drivers into mergable shape.
We also merge, and then revert, the ktap code, as Ingo and the other
perf/ftrace developers feel it should go into the "real" part of the
kernel with only a bit more work, so no need to put it in staging for
now.
All of this has been in linux-next for a while with no reported
issues"
* tag 'staging-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (1045 commits)
staging: drm/imx: fix return value check in ipu_add_subdevice_pdata()
Staging: zram: Fix access of NULL pointer
Staging: zram: Fix variable dereferenced before check
Staging: rtl8187se: space prohibited before semicolon in r8185b_init.c
Staging: rtl8187se: fix space prohibited after that open parenthesis '(' in r8185b_init.c
Staging: rtl8187se: fix braces {} are not necessary for single statement blocks in r8185b_init.c
Staging: rtl8187se: fix trailing whitespace in r8185b_init.c
Staging: rtl8187se: fix please, no space before tabs in r8185b_init.c
drivers/staging/nvec/Kconfig: remove trailing whitespace
Staging: dwc2: Fix variable dereferenced before check
Staging: xgifb: fix braces {} are not necessary for any arm of this statement
staging: rtl8192e: remove unneeded semicolons
staging: rtl8192e: use true and false for bool variables
staging: ft1000: return values corrected in scram_start_dwnld
staging: ft1000: change values of status return variable in write_dpram32_and_check
staging: bcm: Remove unnecessary pointer casting
imx-drm: ipuv3-crtc: Invert IPU DI0 clock polarity
staging: r8188eu: Fix sparse warnings in rtl_p2p.c
staging: r8188eu: Fix sparse warnings in rtw_mlme_ext.c
staging: r8188eu: Fix sparse warnings in rtl8188e.cmd.c
...
Here's the big tty/serial driver update for 3.13-rc1.
There's some more minor n_tty work here, but nothing like previous
kernel releases. Also some new driver ids, driver updates for new
hardware, and other small things.
All of this has been in linux-next for a while with no issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.19 (GNU/Linux)
iEYEABECAAYFAlJ6xnEACgkQMUfUDdst+ylj1QCfaIzUNuFfzTmyB6K6iZrRNhCc
WPgAnRLkkEpI/3rRo7jKwGQsuIuyybUu
=r149
-----END PGP SIGNATURE-----
Merge tag 'tty-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver updates from Greg KH:
"Here's the big tty/serial driver update for 3.13-rc1.
There's some more minor n_tty work here, but nothing like previous
kernel releases. Also some new driver ids, driver updates for new
hardware, and other small things.
All of this has been in linux-next for a while with no issues"
* tag 'tty-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (84 commits)
serial: omap: fix missing comma
serial: sh-sci: Enable the driver on all ARM platforms
serial: mfd: Staticize local symbols
serial: omap: fix a few checkpatch warnings
serial: omap: improve RS-485 performance
mrst_max3110: fix unbalanced IRQ issue during resume
serial: omap: Add support for optional wake-up
serial: sirf: remove duplicate defines
tty: xuartps: Fix build error when COMMON_CLK is not set
tty: xuartps: Fix build error due to missing forward declaration
tty: xuartps: Fix "may be used uninitialized" build warning
serial: 8250_pci: add Pericom PCIe Serial board Support (12d8:7952/4/8) - Chip PI7C9X7952/4/8
tty: xuartps: Update copyright information
tty: xuartps: Implement suspend/resume callbacks
tty: xuartps: Dynamically adjust to input frequency changes
tty: xuartps: Updating set_baud_rate()
tty: xuartps: Force enable the UART in xuartps_console_write
tty: xuartps: support 64 byte FIFO size
tty: xuartps: Add polled mode support for xuartps
tty: xuartps: Implement BREAK detection, add SYSRQ support
...
Here's the big driver core / sysfs update for 3.13-rc1.
There's lots of dev_groups updates for different subsystems, as they all
get slowly migrated over to the safe versions of the attribute groups
(removing userspace races with the creation of the sysfs files.) Also
in here are some kobject updates, devres expansions, and the first round
of Tejun's sysfs reworking to enable it to be used by other subsystems
as a backend for an in-kernel filesystem.
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.19 (GNU/Linux)
iEYEABECAAYFAlJ6xAMACgkQMUfUDdst+yk1kQCfcHXhfnrvFZ5J/mDP509IzhNS
ddEAoLEWoivtBppNsgrWqXpD1vi4UMsE
=JmVW
-----END PGP SIGNATURE-----
Merge tag 'driver-core-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core / sysfs patches from Greg KH:
"Here's the big driver core / sysfs update for 3.13-rc1.
There's lots of dev_groups updates for different subsystems, as they
all get slowly migrated over to the safe versions of the attribute
groups (removing userspace races with the creation of the sysfs
files.) Also in here are some kobject updates, devres expansions, and
the first round of Tejun's sysfs reworking to enable it to be used by
other subsystems as a backend for an in-kernel filesystem.
All of these have been in linux-next for a while with no reported
issues"
* tag 'driver-core-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (83 commits)
sysfs: rename sysfs_assoc_lock and explain what it's about
sysfs: use generic_file_llseek() for sysfs_file_operations
sysfs: return correct error code on unimplemented mmap()
mdio_bus: convert bus code to use dev_groups
device: Make dev_WARN/dev_WARN_ONCE print device as well as driver name
sysfs: separate out dup filename warning into a separate function
sysfs: move sysfs_hash_and_remove() to fs/sysfs/dir.c
sysfs: remove unused sysfs_get_dentry() prototype
sysfs: honor bin_attr.attr.ignore_lockdep
sysfs: merge sysfs_elem_bin_attr into sysfs_elem_attr
devres: restore zeroing behavior of devres_alloc()
sysfs: fix sysfs_write_file for bin file
input: gameport: convert bus code to use dev_groups
input: serio: remove bus usage of dev_attrs
input: serio: use DEVICE_ATTR_RO()
i2o: convert bus code to use dev_groups
memstick: convert bus code to use dev_groups
tifm: convert bus code to use dev_groups
virtio: convert bus code to use dev_groups
ipack: convert bus code to use dev_groups
...
This reverts commit e37f14a5fb.
It turned out other systems also share the same problem with bug 63111
so I made a patch to catch initial brightness level 0 problem. With that
patch applied, we do not need to place HP 250 G1 in DMI table.
References: https://bugzilla.kernel.org/show_bug.cgi?id=63111
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Some firmware doesn't initialize initial backlight level to a proper
value and _BQC will return 0 on first time evaluation. We used to be
able to detect such incorrect value with our code logic, as value 0
normally isn't a valid value in _BCL. But with the introduction of Win8,
firmware begins to fill _BCL with values from 0 to 100, now 0 becomes
a valid value but that value will make user's screen black. This patch
test initial _BQC for value 0, if such a value is returned, do not use
it.
References: https://bugzilla.kernel.org/show_bug.cgi?id=64031
References: https://bugzilla.kernel.org/show_bug.cgi?id=61231
References: https://bugzilla.kernel.org/show_bug.cgi?id=63111
Reported-by: Qingshuai Tian <qingshuai.tian@intel.com>
Tested-by: Aaron Lu <aaron.lu@intel.com> # on "Idealpad u330p"
Reported-and-tested-by: <erno@iki.fi> # on "Acer Aspire V5-573G"
Reported-and-tested-by: Kirill Tkhai <tkhai@yandex.ru> # on "HP 250 G1"
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>