diff options
| author | Guenter Roeck <linux@roeck-us.net> | 2019-04-04 11:16:20 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-31 06:48:24 -0700 |
| commit | 9e1261a92248c07c5df4b3bc694122ef0f9de255 (patch) | |
| tree | 558fdd2374c40e1853c7828edab90ac8befe5f97 /drivers/hwmon | |
| parent | a7f8e2d504b500d6eca7e0b4992d6b05ceb59de0 (diff) | |
hwmon: (pc87427) Use request_muxed_region for Super-IO accesses
[ Upstream commit 755a9b0f8aaa5639ba5671ca50080852babb89ce ]
Super-IO accesses may fail on a system with no or unmapped LPC bus.
Also, other drivers may attempt to access the LPC bus at the same time,
resulting in undefined behavior.
Use request_muxed_region() to ensure that IO access on the requested
address space is supported, and to ensure that access by multiple drivers
is synchronized.
Fixes: ba224e2c4f0a7 ("hwmon: New PC87427 hardware monitoring driver")
Reported-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reported-by: John Garry <john.garry@huawei.com>
Cc: John Garry <john.garry@huawei.com>
Acked-by: John Garry <john.garry@huawei.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/hwmon')
| -rw-r--r-- | drivers/hwmon/pc87427.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/drivers/hwmon/pc87427.c b/drivers/hwmon/pc87427.c index cb9fdd37bd0d..2b5b8c3de8fc 100644 --- a/drivers/hwmon/pc87427.c +++ b/drivers/hwmon/pc87427.c @@ -106,6 +106,13 @@ static const char *logdev_str[2] = { DRVNAME " FMC", DRVNAME " HMC" }; #define LD_IN 1 #define LD_TEMP 1 +static inline int superio_enter(int sioaddr) +{ + if (!request_muxed_region(sioaddr, 2, DRVNAME)) + return -EBUSY; + return 0; +} + static inline void superio_outb(int sioaddr, int reg, int val) { outb(reg, sioaddr); @@ -122,6 +129,7 @@ static inline void superio_exit(int sioaddr) { outb(0x02, sioaddr); outb(0x02, sioaddr + 1); + release_region(sioaddr, 2); } /* @@ -1220,7 +1228,11 @@ static int __init pc87427_find(int sioaddr, struct pc87427_sio_data *sio_data) { u16 val; u8 cfg, cfg_b; - int i, err = 0; + int i, err; + + err = superio_enter(sioaddr); + if (err) + return err; /* Identify device */ val = force_id ? force_id : superio_inb(sioaddr, SIOREG_DEVID); |