From 5ce6185c2ef4e5bcb268f0fdbfca90e787e1bf6d Mon Sep 17 00:00:00 2001 From: Finn Thain Date: Tue, 11 Sep 2018 20:18:44 -0400 Subject: [PATCH] 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 Signed-off-by: Finn Thain Signed-off-by: Michael Ellerman --- drivers/macintosh/via-macii.c | 26 ++++++++++++++++++-------- 1 file 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; } -- 2.11.0