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authorFinn Thain <fthain@telegraphics.com.au>2018-09-12 03:18:44 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2018-10-08 14:53:10 +0300
commit5ce6185c2ef4e5bcb268f0fdbfca90e787e1bf6d (patch)
tree9424be1885328bf4e4c32a475c9abd2f6301dde3 /drivers/macintosh/via-macii.c
parent5f93d7081a47e1972031ccf57c4b2779eee162fb (diff)
downloadlinux-5ce6185c2ef4e5bcb268f0fdbfca90e787e1bf6d.tar.xz
macintosh/via-macii: Simplify locking
Modifying the request queue or changing the current state requires mutual exclusion. Use local_irq_disable() consistently for this rather than disabling the ADB interrupt. This simplifies the locking scheme and brings via-macii into line with the other ADB drivers. Tested-by: Stan Johnson <userm57@yahoo.com> Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'drivers/macintosh/via-macii.c')
-rw-r--r--drivers/macintosh/via-macii.c26
1 files changed, 18 insertions, 8 deletions
diff --git a/drivers/macintosh/via-macii.c b/drivers/macintosh/via-macii.c
index 7e0e32fa7eb2..6ed9ac91aca1 100644
--- a/drivers/macintosh/via-macii.c
+++ b/drivers/macintosh/via-macii.c
@@ -216,22 +216,23 @@ static void macii_queue_poll(void)
static int macii_send_request(struct adb_request *req, int sync)
{
int err;
- unsigned long flags;
- local_irq_save(flags);
err = macii_write(req);
- local_irq_restore(flags);
+ if (err)
+ return err;
- if (!err && sync)
+ if (sync)
while (!req->complete)
macii_poll();
- return err;
+ return 0;
}
/* Send an ADB request (append to request queue) */
static int macii_write(struct adb_request *req)
{
+ unsigned long flags;
+
if (req->nbytes < 2 || req->data[0] != ADB_PACKET || req->nbytes > 15) {
req->complete = 1;
return -EINVAL;
@@ -242,6 +243,8 @@ static int macii_write(struct adb_request *req)
req->complete = 0;
req->reply_len = 0;
+ local_irq_save(flags);
+
if (current_req != NULL) {
last_req->next = req;
last_req = req;
@@ -250,6 +253,9 @@ static int macii_write(struct adb_request *req)
last_req = req;
if (macii_state == idle) macii_start();
}
+
+ local_irq_restore(flags);
+
return 0;
}
@@ -293,9 +299,7 @@ static inline int need_autopoll(void) {
/* Prod the chip without interrupts */
static void macii_poll(void)
{
- disable_irq(IRQ_MAC_ADB);
macii_interrupt(0, NULL);
- enable_irq(IRQ_MAC_ADB);
}
/* Reset the bus */
@@ -358,13 +362,18 @@ static irqreturn_t macii_interrupt(int irq, void *arg)
{
int x;
struct adb_request *req;
+ unsigned long flags;
+
+ local_irq_save(flags);
if (!arg) {
/* Clear the SR IRQ flag when polling. */
if (via[IFR] & SR_INT)
via[IFR] = SR_INT;
- else
+ else {
+ local_irq_restore(flags);
return IRQ_NONE;
+ }
}
last_status = status;
@@ -512,5 +521,6 @@ static irqreturn_t macii_interrupt(int irq, void *arg)
break;
}
+ local_irq_restore(flags);
return IRQ_HANDLED;
}