From 519e23a7f51e853dbe5dc4abb193c0c0db303b3a Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Fri, 10 Feb 2017 11:27:57 +0100 Subject: [PATCH] i2c: designware-baytrail: Fix race when resetting the semaphore 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 Reviewed-by: Andy Shevchenko Acked-by: Jarkko Nikula Acked-by: Wolfram Sang Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/20170210102802.20898-8-hdegoede@redhat.com --- drivers/i2c/busses/i2c-designware-baytrail.c | 11 ++--------- 1 file changed, 2 insertions(+), 9 deletions(-) diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c index 650a700f215e..8df529c04f8e 100644 --- a/drivers/i2c/busses/i2c-designware-baytrail.c +++ b/drivers/i2c/busses/i2c-designware-baytrail.c @@ -47,15 +47,8 @@ static int get_sem(struct dw_i2c_dev *dev, u32 *sem) static void reset_semaphore(struct dw_i2c_dev *dev) { - u32 data; - - if (iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, PUNIT_SEMAPHORE, &data)) { - dev_err(dev->dev, "iosf failed to reset punit semaphore during read\n"); - return; - } - - data &= ~PUNIT_SEMAPHORE_BIT; - if (iosf_mbi_write(BT_MBI_UNIT_PMC, MBI_REG_WRITE, PUNIT_SEMAPHORE, data)) + if (iosf_mbi_modify(BT_MBI_UNIT_PMC, MBI_REG_READ, PUNIT_SEMAPHORE, + 0, PUNIT_SEMAPHORE_BIT)) dev_err(dev->dev, "iosf failed to reset punit semaphore during write\n"); pm_qos_update_request(&dev->pm_qos, PM_QOS_DEFAULT_VALUE);