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authorHans de Goede <hdegoede@redhat.com>2017-02-10 13:27:59 +0300
committerDaniel Vetter <daniel.vetter@ffwll.ch>2017-03-02 17:46:35 +0300
commit5b2cacceb7a877f5eea60ffc7bb6ccd62c4d51cc (patch)
tree13b4bed1050c730504b2554e3c9e177d236f9f92 /drivers/i2c/busses/i2c-designware-baytrail.c
parentfd476fa22a1f432658b799b023f351f291f2db8b (diff)
downloadlinux-5b2cacceb7a877f5eea60ffc7bb6ccd62c4d51cc.tar.xz
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/i2c-designware-baytrail.c')
-rw-r--r--drivers/i2c/busses/i2c-designware-baytrail.c4
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