Commit bbb27fc3 authored by Ricardo Ribalda's avatar Ricardo Ribalda Committed by Wolfram Sang

i2c: piix4: Request the SMBUS semaphore inside the mutex

SMBSLVCNT must be protected with the piix4_mutex_sb800 in order to avoid
multiple buses accessing to the semaphore at the same time.

Fixes: 701dc207 ("i2c: piix4: Avoid race conditions with IMC")
Reported-by: default avatarJean Delvare <jdelvare@suse.de>
Signed-off-by: default avatarRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: default avatarJean Delvare <jdelvare@suse.de>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent f43128c7
...@@ -592,6 +592,8 @@ static s32 piix4_access_sb800(struct i2c_adapter *adap, u16 addr, ...@@ -592,6 +592,8 @@ static s32 piix4_access_sb800(struct i2c_adapter *adap, u16 addr,
u8 port; u8 port;
int retval; int retval;
mutex_lock(&piix4_mutex_sb800);
/* Request the SMBUS semaphore, avoid conflicts with the IMC */ /* Request the SMBUS semaphore, avoid conflicts with the IMC */
smbslvcnt = inb_p(SMBSLVCNT); smbslvcnt = inb_p(SMBSLVCNT);
do { do {
...@@ -605,10 +607,10 @@ static s32 piix4_access_sb800(struct i2c_adapter *adap, u16 addr, ...@@ -605,10 +607,10 @@ static s32 piix4_access_sb800(struct i2c_adapter *adap, u16 addr,
usleep_range(1000, 2000); usleep_range(1000, 2000);
} while (--retries); } while (--retries);
/* SMBus is still owned by the IMC, we give up */ /* SMBus is still owned by the IMC, we give up */
if (!retries) if (!retries) {
mutex_unlock(&piix4_mutex_sb800);
return -EBUSY; return -EBUSY;
}
mutex_lock(&piix4_mutex_sb800);
outb_p(piix4_port_sel_sb800, SB800_PIIX4_SMB_IDX); outb_p(piix4_port_sel_sb800, SB800_PIIX4_SMB_IDX);
smba_en_lo = inb_p(SB800_PIIX4_SMB_IDX + 1); smba_en_lo = inb_p(SB800_PIIX4_SMB_IDX + 1);
...@@ -623,11 +625,11 @@ static s32 piix4_access_sb800(struct i2c_adapter *adap, u16 addr, ...@@ -623,11 +625,11 @@ static s32 piix4_access_sb800(struct i2c_adapter *adap, u16 addr,
outb_p(smba_en_lo, SB800_PIIX4_SMB_IDX + 1); outb_p(smba_en_lo, SB800_PIIX4_SMB_IDX + 1);
mutex_unlock(&piix4_mutex_sb800);
/* Release the semaphore */ /* Release the semaphore */
outb_p(smbslvcnt | 0x20, SMBSLVCNT); outb_p(smbslvcnt | 0x20, SMBSLVCNT);
mutex_unlock(&piix4_mutex_sb800);
return retval; return retval;
} }
......
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