This patch patch applies a common fix to all IT87 driver. Separating it into 2 patches (one for drivers/hwmon and one for drivers/watchdog) does not seem to be the right thing to do. I think having all the patches in one file makes it easier to understand the rationale behind the patch. The it87_io_lock.c and it87_io_lock.h files are in drivers/watchdog directory and the lock defined in it is needed by the changes in drivers/hwmon/it87.c
Regards
Nat
On Tue, Apr 5, 2011 at 3:38 PM, Guenter Roeck <guenter.roeck@xxxxxxxxxxxx> wrote:
Seems to me those should be separate patches, one per affected subsystem.On Tue, Apr 05, 2011 at 05:24:57PM -0400, Nat Gurumoorthy wrote:
> There are 3 different drivers that touch the it87 hardware registers.
> The 3 drivers have been written independently and access the it87 hardware
> registers assuming they are the only driver accessing it. This change
> attempts to serialize access to the hardware by defining a global spinlock
> it87_io_lock in a file it87_lock.c. This lock has to be acquired by each
> of the it87 drivers before it can access the hardware. We have defined
> a new Kconfig option IT87_LOCK. When it is selected it87_lock.c is compiled
> into the kernel thereby making the lock global and accessable to the it87
> drivers which are typically built as loadable modules. All the it87 drivers
> select IT87_LOCK to compile the lock into the kernel.
> The routines accessing the hardware are being called from module init,
> open, ioctl and module exit routines and hence it is sufficient to use
> calls to spin_lock and spin_unlock to acquire and release the locks. For
> the same reasons it87_wdt.c has extensive changes to remove calls to
> spin_lock_irqsave and spin_unlock_irqrestore. The lock is now acquired
> in superio_enter and released in superio_exit. This is now identical
> to the code in drivers/hwmon/it87.c and drivers/watchdog/it8712f_wdt.c.
> Added __acquire and __release annotations wherever needed.
> ---
> drivers/hwmon/Kconfig | 1 +
> drivers/hwmon/it87.c | 14 ++++++++++++-
> drivers/watchdog/Kconfig | 12 +++++++++++
> drivers/watchdog/Makefile | 1 +
> drivers/watchdog/it8712f_wdt.c | 10 ++++----
> drivers/watchdog/it87_lock.c | 27 +++++++++++++++++++++++++
> drivers/watchdog/it87_wdt.c | 42 ++++++---------------------------------
> include/linux/it87_lock.h | 28 ++++++++++++++++++++++++++
> 8 files changed, 94 insertions(+), 41 deletions(-)
> create mode 100644 drivers/watchdog/it87_lock.c
> create mode 100644 include/linux/it87_lock.h
>
> Signed-off-by: Nat Gurumoorthy <natg@xxxxxxxxxx>
>
Guenter
--
Regards
Nat Gurumoorthy AB6SJ
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