summary refs log tree commit diff
path: root/drivers/macintosh/adb-iop.c
diff options
context:
space:
mode:
authorFinn Thain <fthain@telegraphics.com.au>2021-01-18 17:19:40 +1100
committerGeert Uytterhoeven <geert@linux-m68k.org>2021-01-25 13:23:38 +0100
commitc396dd2ec5bbd1cb80eafe32a72ab6bd6b17cb5a (patch)
treecd9493bf6682e9259e7e465d6594445d05c7ce9c /drivers/macintosh/adb-iop.c
parentab5cbfc2fe014421c36b52521a8d5f6241f08455 (diff)
downloadlinux-c396dd2ec5bbd1cb80eafe32a72ab6bd6b17cb5a.tar.gz
macintosh/adb-iop: Use big-endian autopoll mask
As usual, the available documentation is inadequate and leaves endianness
unspecified for message data. However, testing shows that this patch does
improve correctness. The mistake should have been detected earlier but it
was obscured by other bugs. In testing, this patch reinstated pre-v5.9
behaviour. The old driver bugs remain and ADB input devices may stop
working. But that appears to be unrelated.

Cc: Joshua Thompson <funaho@jurai.org>
Fixes: c66da95a39ec ("macintosh/adb-iop: Implement SRQ autopolling")
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/20210125074524.3027452-1-geert@linux-m68k.org
Diffstat (limited to 'drivers/macintosh/adb-iop.c')
-rw-r--r--drivers/macintosh/adb-iop.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/macintosh/adb-iop.c b/drivers/macintosh/adb-iop.c
index 0ee327249150..2633bc254935 100644
--- a/drivers/macintosh/adb-iop.c
+++ b/drivers/macintosh/adb-iop.c
@@ -19,6 +19,7 @@
 #include <asm/macints.h>
 #include <asm/mac_iop.h>
 #include <asm/adb_iop.h>
+#include <asm/unaligned.h>
 
 #include <linux/adb.h>
 
@@ -249,7 +250,7 @@ static void adb_iop_set_ap_complete(struct iop_msg *msg)
 {
 	struct adb_iopmsg *amsg = (struct adb_iopmsg *)msg->message;
 
-	autopoll_devs = (amsg->data[1] << 8) | amsg->data[0];
+	autopoll_devs = get_unaligned_be16(amsg->data);
 	if (autopoll_devs & (1 << autopoll_addr))
 		return;
 	autopoll_addr = autopoll_devs ? (ffs(autopoll_devs) - 1) : 0;
@@ -266,8 +267,7 @@ static int adb_iop_autopoll(int devs)
 	amsg.flags = ADB_IOP_SET_AUTOPOLL | (mask ? ADB_IOP_AUTOPOLL : 0);
 	amsg.count = 2;
 	amsg.cmd = 0;
-	amsg.data[0] = mask & 0xFF;
-	amsg.data[1] = (mask >> 8) & 0xFF;
+	put_unaligned_be16(mask, amsg.data);
 
 	iop_send_message(ADB_IOP, ADB_CHAN, NULL, sizeof(amsg), (__u8 *)&amsg,
 			 adb_iop_set_ap_complete);