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@xxxxxxxxxx> Tested-by: tagorereddy <tagore.chandan@xxxxxxxxx> Acked-by: Wolfram Sang <wsa@xxxxxxxxxxxxx> --- 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(+) 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 -- 2.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
