On Fri, Mar 15, 2013 at 09:00:35AM -0400, Eduardo Valentin wrote: > Because there is a need to lock inside IRQ handler, this patch > changes the locking mechanism inside the omap-bandgap.[c,h] to > spinlocks. Now this lock is used to protect omap_bandgap struct > during APIs exposed (possibly used in sysfs handling functions) > and inside the ALERT IRQ handler. > > Because there are registers shared among the sensors, this lock > is global, not per sensor. > > Signed-off-by: Eduardo Valentin <eduardo.valentin@xxxxxx> > --- > drivers/staging/omap-thermal/TODO | 1 - > drivers/staging/omap-thermal/omap-bandgap.c | 18 ++++++++++-------- > drivers/staging/omap-thermal/omap-bandgap.h | 4 ++-- > 3 files changed, 12 insertions(+), 11 deletions(-) > > diff --git a/drivers/staging/omap-thermal/TODO b/drivers/staging/omap-thermal/TODO > index 77b761b..0f24e9b 100644 > --- a/drivers/staging/omap-thermal/TODO > +++ b/drivers/staging/omap-thermal/TODO > @@ -1,7 +1,6 @@ > List of TODOs (by Eduardo Valentin) > > on omap-bandgap.c: > -- Rework locking > - Improve driver code by adding usage of regmap-mmio > - Test every exposed API to userland > - Add support to hwmon > diff --git a/drivers/staging/omap-thermal/omap-bandgap.c b/drivers/staging/omap-thermal/omap-bandgap.c > index 4b631fd..846ced6 100644 > --- a/drivers/staging/omap-thermal/omap-bandgap.c > +++ b/drivers/staging/omap-thermal/omap-bandgap.c > @@ -33,7 +33,7 @@ > #include <linux/platform_device.h> > #include <linux/err.h> > #include <linux/types.h> > -#include <linux/mutex.h> > +#include <linux/spinlock.h> > #include <linux/reboot.h> > #include <linux/of_device.h> > #include <linux/of_platform.h> > @@ -170,6 +170,7 @@ static irqreturn_t omap_bandgap_talert_irq_handler(int irq, void *data) > u32 t_hot = 0, t_cold = 0, ctrl; > int i; > > + spin_lock(&bg_ptr->lock); > for (i = 0; i < bg_ptr->conf->sensor_count; i++) { > tsr = bg_ptr->conf->sensors[i].registers; > ctrl = omap_bandgap_readl(bg_ptr, tsr->bgap_status); > @@ -208,6 +209,7 @@ static irqreturn_t omap_bandgap_talert_irq_handler(int irq, void *data) > if (bg_ptr->conf->report_temperature) > bg_ptr->conf->report_temperature(bg_ptr, i); > } > + spin_unlock(&bg_ptr->lock); > > return IRQ_HANDLED; > } > @@ -502,9 +504,9 @@ int _omap_bandgap_write_threshold(struct omap_bandgap *bg_ptr, int id, int val, > if (ret < 0) > goto exit; > > - mutex_lock(&bg_ptr->bg_mutex); > + spin_lock(&bg_ptr->lock); These need to disable interrupts because we take the spin lock in the IRQ handler. regards, dan carpenter -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html