diff options
| author | Guenter Roeck | 2019-04-04 11:16:20 -0700 |
|---|---|---|
| committer | Guenter Roeck | 2019-04-15 17:19:53 -0700 |
| commit | 755a9b0f8aaa5639ba5671ca50080852babb89ce (patch) | |
| tree | 6958c6737518debed2b2dad91a2181401edddb13 /drivers | |
| parent | 73e6ff71a7ea924fb7121d576a2d41e3be3fc6b5 (diff) | |
hwmon: (pc87427) Use request_muxed_region for Super-IO accesses
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>
Diffstat (limited to 'drivers')
| -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 d1a3f2040c00..58eee8fa3e6d 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); } /* @@ -1195,7 +1203,11 @@ 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); |