| Message ID | 20170123210958.18410-10-hdegoede@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 01/23/2017 11:09 PM, Hans de Goede wrote: > 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> > --- > Changes in v2: > -Spelling: P-Unit, PMIC > -Adjust for iosf_mbi_punit_lock/_unlock to _acquire/_release rename > --- > drivers/i2c/busses/i2c-designware-baytrail.c | 4 ++++ > 1 file changed, 4 insertions(+) > Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c index 3effc9a..7eddc3b 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