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| author | Hans de Goede <hdegoede@redhat.com> | 2017-02-10 11:27:59 +0100 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2017-03-02 15:46:35 +0100 |
| commit | 5b2cacceb7a877f5eea60ffc7bb6ccd62c4d51cc (patch) | |
| tree | 13b4bed1050c730504b2554e3c9e177d236f9f92 /drivers/i2c/busses | |
| parent | fd476fa22a1f432658b799b023f351f291f2db8b (diff) | |
| download | linux-5b2cacceb7a877f5eea60ffc7bb6ccd62c4d51cc.tar.bz2 | |
i2c: designware-baytrail: Acquire P-Unit access on bus acquire
Acquire P-Unit access to stop others from accessing the P-Unit while the
PMIC i2c bus is in use. This is necessary because accessing the P-Unit
from the kernel may result in the P-Unit trying to access the PMIC i2c
bus, which results in a hang when it happens while we own the PMIC i2c
bus semaphore.
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=155241
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: tagorereddy <tagore.chandan@gmail.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170210102802.20898-10-hdegoede@redhat.com
Diffstat (limited to 'drivers/i2c/busses')
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-baytrail.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c index 3effc9a1778c..7eddc3b38852 100644 --- a/drivers/i2c/busses/i2c-designware-baytrail.c +++ b/drivers/i2c/busses/i2c-designware-baytrail.c @@ -62,6 +62,8 @@ static void reset_semaphore(struct dw_i2c_dev *dev) dev_err(dev->dev, "iosf failed to reset punit semaphore during write\n"); pm_qos_update_request(&dev->pm_qos, PM_QOS_DEFAULT_VALUE); + + iosf_mbi_punit_release(); } static int baytrail_i2c_acquire(struct dw_i2c_dev *dev) @@ -79,6 +81,8 @@ static int baytrail_i2c_acquire(struct dw_i2c_dev *dev) if (!dev->release_lock) return 0; + iosf_mbi_punit_acquire(); + /* * Disallow the CPU to enter C6 or C7 state, entering these states * requires the punit to talk to the pmic and if this happens while |