From: Hans de Goede <hdegoede@redhat.com>
To: "Daniel Vetter" <daniel.vetter@intel.com>,
"Jani Nikula" <jani.nikula@linux.intel.com>,
"Ville Syrjälä" <ville.syrjala@linux.intel.com>,
"Jarkko Nikula" <jarkko.nikula@linux.intel.com>,
"Wolfram Sang" <wsa@the-dreams.de>,
"Andy Shevchenko" <andriy.shevchenko@linux.intel.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"H . Peter Anvin" <hpa@zytor.com>
Cc: Takashi Iwai <tiwai@suse.de>,
"russianneuromancer @ ya . ru" <russianneuromancer@ya.ru>,
intel-gfx <intel-gfx@lists.freedesktop.org>,
Hans de Goede <hdegoede@redhat.com>,
linux-i2c@vger.kernel.org,
Mika Westerberg <mika.westerberg@linux.intel.com>
Subject: [PATCH v4 07/12] i2c: designware-baytrail: Fix race when resetting the semaphore
Date: Fri, 24 Feb 2017 10:29:07 +0100 [thread overview]
Message-ID: <20170224092912.10685-8-hdegoede@redhat.com> (raw)
In-Reply-To: <20170224092912.10685-1-hdegoede@redhat.com>
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: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
---
Changes in v5:
-New patch in v5 of this patch-set
---
drivers/i2c/busses/i2c-designware-baytrail.c | 11 ++---------
1 file changed, 2 insertions(+), 9 deletions(-)
diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c
index 650a700..8df529c 100644
--- a/drivers/i2c/busses/i2c-designware-baytrail.c
+++ b/drivers/i2c/busses/i2c-designware-baytrail.c
@@ -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);
--
2.9.3
_______________________________________________
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next prev parent reply other threads:[~2017-02-24 9:29 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-24 9:29 [PATCH v4 00/12] coordinate cht i2c-pmic and i915-punit accesses Hans de Goede
2017-02-24 9:29 ` [PATCH v4 01/12] x86/platform/intel/iosf_mbi: Add a mutex for P-Unit access Hans de Goede
2017-02-24 9:29 ` [PATCH v4 02/12] x86/platform/intel/iosf_mbi: Add a PMIC bus access notifier Hans de Goede
2017-02-24 9:29 ` [PATCH v4 03/12] i2c: designware: Rename accessor_flags to flags Hans de Goede
2017-02-24 9:29 ` [PATCH v4 04/12] i2c: designware-baytrail: Pass dw_i2c_dev into helper functions Hans de Goede
2017-02-24 9:29 ` [PATCH v4 05/12] i2c: designware-baytrail: Only check iosf_mbi_available() for shared hosts Hans de Goede
2017-02-24 9:29 ` [PATCH v4 06/12] i2c: designware-baytrail: Disallow the CPU to enter C6 or C7 while holding the punit semaphore Hans de Goede
2017-02-24 9:29 ` Hans de Goede [this message]
2017-02-24 9:29 ` [PATCH v4 08/12] i2c: designware-baytrail: Add support for cherrytrail Hans de Goede
2017-02-24 9:29 ` [PATCH v4 09/12] i2c: designware-baytrail: Acquire P-Unit access on bus acquire Hans de Goede
2017-02-24 9:29 ` [PATCH v4 10/12] i2c: designware-baytrail: Call pmic_bus_access_notifier_chain Hans de Goede
2017-02-24 9:29 ` [PATCH v4 11/12] drm/i915: Add intel_uncore_suspend / resume functions Hans de Goede
2017-02-24 9:29 ` [PATCH v4 12/12] drm/i915: Listen for PMIC bus access notifications Hans de Goede
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