For race free unregistration drivers may need to acquire PMIC bus access
through iosf_mbi_punit_acquire() and then (un)register the notifier without
dropping the lock.
This commit adds an unlocked variant of
iosf_mbi_unregister_pmic_bus_access_notifier for this use case.
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171019111620.26761-2-hdegoede@redhat.com
Some drivers may need to acquire P-Unit managed resources from interrupt
context, where they cannot call iosf_mbi_punit_acquire().
This commit adds a notifier chain which allows a driver to get notified
(in a process context) before other drivers start accessing the PMIC bus,
so that the driver can acquire any resources, which it may need during
the window the other driver is accessing the PMIC, before hand.
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>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
One some systems the P-Unit accesses the PMIC to change various voltages
through the same bus as other kernel drivers use for e.g. battery
monitoring.
If a driver sends requests to the P-Unit which require the P-Unit to access
the PMIC bus while another driver is also accessing the PMIC bus various
bad things happen.
This commit adds a mutex to protect the P-Unit against simultaneous
accesses and 2 functions to lock / unlock this mutex.
Note on these systems the i2c-bus driver will request a sempahore from the
P-Unit for exclusive access to the PMIC bus when i2c drivers are accessing
it, but this does not appear to be sufficient, we still need to avoid
making certain P-Unit requests during the access window to avoid problems.
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>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170210102802.20898-2-hdegoede@redhat.com
- Move the static variables to one place
- Fix indentations in the header
- Correct comments
No functional change.
[ tglx: Massaged changelog ]
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: David E . Box <david.e.box@linux.intel.com>
Link: http://lkml.kernel.org/r/1436366709-17683-5-git-send-email-andriy.shevchenko@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The code checks the result of the first debugfs_create call several
times and fails to check the result of the subsequent calls due to
missing assigments.
Add the missing assignments and check only for !res because
debugfs_create() returns only NULL on error and not an encoded error
code.
[ tglx: Massaged changelog ]
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: David E . Box <david.e.box@linux.intel.com>
Link: http://lkml.kernel.org/r/1436366709-17683-3-git-send-email-andriy.shevchenko@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Move the driver to arch/x86/platform/intel since it is not a core
kernel code and it is related to many Intel SoCs from different
groups: Atom, MID, etc.
There is no functional change.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: David E . Box <david.e.box@linux.intel.com>
Link: http://lkml.kernel.org/r/1436366709-17683-2-git-send-email-andriy.shevchenko@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Hans de Goede