kernel.git/drivers/hwmon/applesmc.c, branch linux-5.9.y

hwmon: (applesmc) Re-work SMC comms

2020-11-18T18:22:21Z

[ Upstream commit 4d64bb4ba5ecf4831448cdb2fe16d0ae91b2b40b ] Commit fff2d0f701e6 ("hwmon: (applesmc) avoid overlong udelay()") introduced an issue whereby communication with the SMC became unreliable with write errors like : [ 120.378614] applesmc: send_byte(0x00, 0x0300) fail: 0x40 [ 120.378621] applesmc: LKSB: write data fail [ 120.512782] applesmc: send_byte(0x00, 0x0300) fail: 0x40 [ 120.512787] applesmc: LKSB: write data fail The original code appeared to be timing sensitive and was not reliable with the timing changes in the aforementioned commit. This patch re-factors the SMC communication to remove the timing dependencies and restore function with the changes previously committed. Tested on : MacbookAir6,2 MacBookPro11,1 iMac12,2, MacBookAir1,1, MacBookAir3,1 Fixes: fff2d0f701e6 ("hwmon: (applesmc) avoid overlong udelay()") Reported-by: Andreas Kemnade Tested-by: Andreas Kemnade # MacBookAir6,2 Acked-by: Arnd Bergmann Signed-off-by: Brad Campbell Signed-off-by: Henrik Rydberg Link: https://lore.kernel.org/r/194a7d71-a781-765a-d177-c962ef296b90@fnarfbargle.com Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin

hwmon: (applesmc) check status earlier.

2020-08-21T18:32:34Z

clang static analysis reports this representative problem applesmc.c:758:10: warning: 1st function call argument is an uninitialized value left = be16_to_cpu(*(__be16 *)(buffer + 6)) >> 2; ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ buffer is filled by the earlier call ret = applesmc_read_key(LIGHT_SENSOR_LEFT_KEY, ... This problem is reported because a goto skips the status check. Other similar problems use data from applesmc_read_key before checking the status. So move the checks to before the use. Signed-off-by: Tom Rix Reviewed-by: Henrik Rydberg Link: https://lore.kernel.org/r/20200820131932.10590-1-trix@redhat.com Signed-off-by: Guenter Roeck

hwmon: (applesmc) avoid overlong udelay()

2020-05-27T16:18:13Z

Building this driver with "clang -O3" produces a link error after the compiler partially unrolls the loop and 256ms becomes a compile-time constant that triggers the check in udelay(): ld.lld: error: undefined symbol: __bad_udelay >>> referenced by applesmc.c >>> hwmon/applesmc.o:(read_smc) in archive drivers/built-in.a I can see no reason against using a sleeping function here, as no part of the driver runs in atomic context, so instead use usleep_range() with a wide range and use jiffies for the end condition. Signed-off-by: Arnd Bergmann Link: https://lore.kernel.org/r/20200527135207.1118624-1-arnd@arndb.de Signed-off-by: Guenter Roeck

hwmon: (applesmc) switch to using input device polling mode

2019-11-06T22:37:18Z

Now that instances of input_dev support polling mode natively, we no longer need to create input_polled_dev instance. Signed-off-by: Dmitry Torokhov Link: https://lore.kernel.org/r/20191002214345.GA108728@dtor-ws Signed-off-by: Guenter Roeck

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 271

2019-06-05T15:30:30Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license v2 as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 51 franklin street fifth floor boston ma 02110 1301 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Richard Fontana Reviewed-by: Alexios Zavras Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141334.424952652@linutronix.de Signed-off-by: Greg Kroah-Hartman

hwmon: (applesmc) Replace S_ with octal values

2018-12-16T23:13:39Z

Replace S_ with octal values. The conversion was done automatically with coccinelle. The semantic patches and the scripts used to generate this commit log are available at https://github.com/groeck/coccinelle-patches/hwmon/. This patch does not introduce functional changes. It was verified by compiling the old and new files and comparing text and data sizes. Cc: Henrik Rydberg Signed-off-by: Guenter Roeck

dmi: Mark all struct dmi_system_id instances const

2017-09-14T09:59:30Z

... and __initconst if applicable. Based on similar work for an older kernel in the Grsecurity patch. [JD: fix toshiba-wmi build] [JD: add htcpen] [JD: move __initconst where checkscript wants it] Signed-off-by: Christoph Hellwig Signed-off-by: Jean Delvare

hwmon: (applesmc) Avoid buffer overruns

2017-07-15T23:38:56Z

gcc 7.1 complains that the driver uses sprintf() and thus does not validate the length of output buffers. drivers/hwmon/applesmc.c: In function 'applesmc_show_fan_position': drivers/hwmon/applesmc.c:82:21: warning: '%d' directive writing between 1 and 5 bytes into a region of size 4 Fix the problem by using scnprintf() instead of sprintf() throughout the driver. Also explicitly limit the number of supported fans to avoid actual buffer overruns and thus invalid keys. Signed-off-by: Guenter Roeck

hwmon : (applesmc) Fix uninitialized variables warnings

2015-11-16T05:52:39Z

Fix the following "maybe used uninitialized" warnings by initializing the variables to keep the compiler quiet. There is no "used uninitialized" in this case. CC [M] drivers/hwmon/applesmc.o drivers/hwmon/applesmc.c: In function ‘applesmc_init_smcreg’: drivers/hwmon/applesmc.c:595:43: warning: ‘right_light_sensor’ may be used uninitialized in this function [-Wmaybe-uninitialized] s->num_light_sensors = left_light_sensor + right_light_sensor; ^ drivers/hwmon/applesmc.c:540:26: note: ‘right_light_sensor’ was declared here bool left_light_sensor, right_light_sensor; ^ drivers/hwmon/applesmc.c:595:43: warning: ‘left_light_sensor’ may be used uninitialized in this function [-Wmaybe-uninitialized] s->num_light_sensors = left_light_sensor + right_light_sensor; ^ drivers/hwmon/applesmc.c:540:7: note: ‘left_light_sensor’ was declared here bool left_light_sensor, right_light_sensor; ^ Signed-off-by: Shuah Khan Signed-off-by: Guenter Roeck

hwmon: applesmc: fix comment typos

2015-09-29T13:28:01Z

s/ressources/resources/ Signed-off-by: Bastien Nocera Signed-off-by: Jiri Kosina