m68k/mac: Add mutual exclusion for IOP interrupt polling

The IOP interrupt handler iop_ism_irq() is used by the adb-iop
driver to poll for ADB request completion. Unfortunately, it is not
re-entrant. Fix the race condition by adding an iop_ism_irq_poll()
function with suitable mutual exclusion.

Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

diff --git a/arch/m68k/include/asm/mac_iop.h b/arch/m68k/include/asm/mac_iop.h
index 42566fd052bc0e091a4143f9fbd168c40752985c..d2a08e004e2c38b698e819565a6f39ba9a582f56 100644 (file)
--- a/arch/m68k/include/asm/mac_iop.h
+++ b/arch/m68k/include/asm/mac_iop.h
@@ -158,6 +158,7 @@ extern void iop_complete_message(struct iop_msg *);
 extern void iop_upload_code(uint, __u8 *, uint, __u16);
 extern void iop_download_code(uint, __u8 *, uint, __u16);
 extern __u8 *iop_compare_code(uint, __u8 *, uint, __u16);
+extern void iop_ism_irq_poll(uint);
 
 extern void iop_register_interrupts(void);
 

diff --git a/arch/m68k/mac/iop.c b/arch/m68k/mac/iop.c
index a2ea52db7d1845a812b9ef725fd80e91c71a2614..9bfa170157688f1b16859e04d2dd0d3dec10cda8 100644 (file)
--- a/arch/m68k/mac/iop.c
+++ b/arch/m68k/mac/iop.c
@@ -598,3 +598,12 @@ irqreturn_t iop_ism_irq(int irq, void *dev_id)
        }
        return IRQ_HANDLED;
 }
+
+void iop_ism_irq_poll(uint iop_num)
+{
+       unsigned long flags;
+
+       local_irq_save(flags);
+       iop_ism_irq(0, (void *)iop_num);
+       local_irq_restore(flags);
+}

diff --git a/drivers/macintosh/adb-iop.c b/drivers/macintosh/adb-iop.c
index f5f4da3d0b675644963af93f327f03f455368bd8..4b0ad399549787e244799f9bd682e4122bcfbe3d 100644 (file)
--- a/drivers/macintosh/adb-iop.c
+++ b/drivers/macintosh/adb-iop.c
@@ -29,8 +29,6 @@
 
 /*#define DEBUG_ADB_IOP*/
 
-extern void iop_ism_irq(int, void *);
-
 static struct adb_request *current_req;
 static struct adb_request *last_req;
 #if 0
@@ -265,7 +263,7 @@ int adb_iop_autopoll(int devs)
 void adb_iop_poll(void)
 {
        if (adb_iop_state == idle) adb_iop_start();
-       iop_ism_irq(0, (void *) ADB_IOP);
+       iop_ism_irq_poll(ADB_IOP);
 }
 
 int adb_iop_reset_bus(void)