* [PATCH] i2c: designware-baytrail: Fix race when resetting the semaphore
2017-01-01 11:30 [PATCH 0/1] i2c: designware-baytrail: Fix race when resetting the semaphore Hans de Goede
@ 2017-01-01 11:30 ` Hans de Goede
0 siblings, 0 replies; 2+ messages in thread
From: Hans de Goede @ 2017-01-01 11:30 UTC (permalink / raw)
To: Jarkko Nikula, Wolfram Sang, Len Brown, Andy Shevchenko
Cc: Mika Westerberg, Jani Nikula, Ville Syrjälä,
Takashi Iwai, russianneuromancer @ ya . ru, linux-i2c, intel-gfx,
Hans de Goede
Use iosf_mbi_modify instead of iosf_mbi_read + iosf_mbi_write so that
we keep the iosf_mbi_lock locked during the read-modify-write done to
reset the semaphore.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
drivers/i2c/busses/i2c-designware-baytrail.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)
diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c
index 9481411..9634544 100644
--- a/drivers/i2c/busses/i2c-designware-baytrail.c
+++ b/drivers/i2c/busses/i2c-designware-baytrail.c
@@ -64,18 +64,16 @@ static int get_sem(struct dw_i2c_dev *dev, u32 *sem)
static void reset_semaphore(struct dw_i2c_dev *dev)
{
- u32 addr = get_sem_addr(dev);
- u32 data;
+ int ret;
- if (iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, addr, &data)) {
- dev_err(dev->dev, "iosf failed to reset punit semaphore during read\n");
+ ret = iosf_mbi_modify(BT_MBI_UNIT_PMC, MBI_REG_READ, get_sem_addr(dev),
+ 0, PUNIT_SEMAPHORE_BIT);
+ if (ret) {
+ dev_err(dev->dev, "iosf failed to reset punit semaphore: %d\n",
+ ret);
return;
}
- data &= ~PUNIT_SEMAPHORE_BIT;
- if (iosf_mbi_write(BT_MBI_UNIT_PMC, MBI_REG_WRITE, addr, data))
- dev_err(dev->dev, "iosf failed to reset punit semaphore during write\n");
-
pm_qos_update_request(&dev->pm_qos, PM_QOS_DEFAULT_VALUE);
}
--
2.9.3
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