Using guard notation makes the code more compact and error handling
more robust by ensuring that locks are released in all code paths
when control leaves critical section.
Signed-off-by: Dmitry Torokhov <dmitry.torok...@gmail.com>
---
drivers/input/serio/gscps2.c | 114 +++++++++++++++++++----------------
1 file changed, 62 insertions(+), 52 deletions(-)
diff --git a/drivers/input/serio/gscps2.c b/drivers/input/serio/gscps2.c
index d94c01eb3fc9..cf0603d1a113 100644
--- a/drivers/input/serio/gscps2.c
+++ b/drivers/input/serio/gscps2.c
@@ -145,7 +145,6 @@ static void gscps2_flush(struct gscps2port *ps2port)
static inline int gscps2_writeb_output(struct gscps2port *ps2port, u8 data)
{
- unsigned long flags;
char __iomem *addr = ps2port->addr;
if (!wait_TBE(addr)) {
@@ -156,9 +155,8 @@ static inline int gscps2_writeb_output(struct gscps2port
*ps2port, u8 data)
while (gscps2_readb_status(addr) & GSC_STAT_RBNE)
/* wait */;
- spin_lock_irqsave(&ps2port->lock, flags);
- writeb(data, addr+GSC_XMTDATA);
- spin_unlock_irqrestore(&ps2port->lock, flags);
+ scoped_guard(spinlock_irqsave, &ps2port->lock)
+ writeb(data, addr+GSC_XMTDATA);
/* this is ugly, but due to timing of the port it seems to be
necessary. */
mdelay(6);
@@ -177,19 +175,19 @@ static inline int gscps2_writeb_output(struct gscps2port
*ps2port, u8 data)
static void gscps2_enable(struct gscps2port *ps2port, int enable)
{
- unsigned long flags;
u8 data;
/* now enable/disable the port */
- spin_lock_irqsave(&ps2port->lock, flags);
- gscps2_flush(ps2port);
- data = gscps2_readb_control(ps2port->addr);
- if (enable)
- data |= GSC_CTRL_ENBL;
- else
- data &= ~GSC_CTRL_ENBL;
- gscps2_writeb_control(data, ps2port->addr);
- spin_unlock_irqrestore(&ps2port->lock, flags);
+ scoped_guard(spinlock_irqsave, &ps2port->lock) {
+ gscps2_flush(ps2port);
+ data = gscps2_readb_control(ps2port->addr);
+ if (enable)
+ data |= GSC_CTRL_ENBL;
+ else
+ data &= ~GSC_CTRL_ENBL;
+ gscps2_writeb_control(data, ps2port->addr);
+ }
+
wait_TBE(ps2port->addr);
gscps2_flush(ps2port);
}
@@ -203,15 +201,56 @@ static void gscps2_reset(struct gscps2port *ps2port)
unsigned long flags;
/* reset the interface */
- spin_lock_irqsave(&ps2port->lock, flags);
+ guard(spinlock_irqsave)(&ps2port->lock);
gscps2_flush(ps2port);
writeb(0xff, ps2port->addr + GSC_RESET);
gscps2_flush(ps2port);
- spin_unlock_irqrestore(&ps2port->lock, flags);
}
static LIST_HEAD(ps2port_list);
+static void gscps2_read_data(struct gscps2port *ps2port)
+{
+ u8 status;
+
+ do {
+ status = gscps2_readb_status(ps2port->addr);
+ if (!(status & GSC_STAT_RBNE))
+ break;
+
+ ps2port->buffer[ps2port->append].ste = status;
+ ps2port->buffer[ps2port->append].data =
+ gscps2_readb_input(ps2port->addr);
+ } while (true);
+}
+
+static bool gscps2_report_data(struct gscps2port *ps2port)
+{
+ unsigned int rxflags;
+ u8 data, status;
+
+ while (ps2port->act != ps2port->append) {
+ /*
+ * Did new data arrived while we read existing data ?
+ * If yes, exit now and let the new irq handler start
+ * over again.
+ */
+ if (gscps2_readb_status(ps2port->addr) & GSC_STAT_CMPINTR)
+ return true;
+
+ status = ps2port->buffer[ps2port->act].str;
+ data = ps2port->buffer[ps2port->act].data;
+
+ ps2port->act = (ps2port->act + 1) & BUFFER_SIZE;
+ rxflags = ((status & GSC_STAT_TERR) ? SERIO_TIMEOUT : 0 ) |
+ ((status & GSC_STAT_PERR) ? SERIO_PARITY : 0 );
+
+ serio_interrupt(ps2port->port, data, rxflags);
+ }
+
+ return false;
+}
+
/**
* gscps2_interrupt() - Interruption service routine
*
@@ -229,47 +268,18 @@ static irqreturn_t gscps2_interrupt(int irq, void *dev)
struct gscps2port *ps2port;
list_for_each_entry(ps2port, &ps2port_list, node) {
+ guard(spinlock_irqsave)(&ps2port->lock);
- unsigned long flags;
- spin_lock_irqsave(&ps2port->lock, flags);
-
- while ( (ps2port->buffer[ps2port->append].str =
- gscps2_readb_status(ps2port->addr)) & GSC_STAT_RBNE ) {
- ps2port->buffer[ps2port->append].data =
- gscps2_readb_input(ps2port->addr);
- ps2port->append = ((ps2port->append+1) & BUFFER_SIZE);
- }
-
- spin_unlock_irqrestore(&ps2port->lock, flags);
-
+ gscps2_read_data(ps2port);
} /* list_for_each_entry */
/* all data was read from the ports - now report the data to upper
layer */
-
list_for_each_entry(ps2port, &ps2port_list, node) {
-
- while (ps2port->act != ps2port->append) {
-
- unsigned int rxflags;
- u8 data, status;
-
- /* Did new data arrived while we read existing data ?
- If yes, exit now and let the new irq handler start over again */
- if (gscps2_readb_status(ps2port->addr) & GSC_STAT_CMPINTR)
- return IRQ_HANDLED;
-
- status = ps2port->buffer[ps2port->act].str;
- data = ps2port->buffer[ps2port->act].data;
-
- ps2port->act = ((ps2port->act+1) & BUFFER_SIZE);
- rxflags = ((status & GSC_STAT_TERR) ? SERIO_TIMEOUT : 0 ) |
- ((status & GSC_STAT_PERR) ? SERIO_PARITY : 0 );
-
- serio_interrupt(ps2port->port, data, rxflags);
-
- } /* while() */
-
- } /* list_for_each_entry */
+ if (gscps2_report_data(ps2port)) {
+ /* More data ready - break early to restart interrupt */
+ break;
+ }
+ }
return IRQ_HANDLED;
}
--
2.46.0.469.g59c65b2a67-goog
