Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 519e23a7 authored by Hans de Goede's avatar Hans de Goede Committed by Daniel Vetter
Browse files

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: default avatarHans de Goede <hdegoede@redhat.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: default avatarJarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: default avatarWolfram Sang <wsa@the-dreams.de>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170210102802.20898-8-hdegoede@redhat.com
parent 086cb4af

drivers/i2c/busses/i2c-designware-baytrail.c

+2 −9
Original line number Diff line number Diff line
@@ -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);