From aeb445bf2194d83e12e85bf5c65baaf1f093bd8f Mon Sep 17 00:00:00 2001 From: Finn Thain Date: Sun, 31 May 2020 09:12:13 +1000 Subject: m68k: mac: Don't send IOP message until channel is idle In the following sequence of calls, iop_do_send() gets called when the "send" channel is not in the IOP_MSG_IDLE state: iop_ism_irq() iop_handle_send() (msg->handler)() iop_send_message() iop_do_send() Avoid this by testing the channel state before calling iop_do_send(). When sending, and iop_send_queue is empty, call iop_do_send() because the channel is idle. If iop_send_queue is not empty, iop_do_send() will get called later by iop_handle_send(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Finn Thain Tested-by: Stan Johnson Cc: Joshua Thompson Link: https://lore.kernel.org/r/6d667c39e53865661fa5a48f16829d18ed8abe54.1590880333.git.fthain@telegraphics.com.au Signed-off-by: Geert Uytterhoeven --- arch/m68k/mac/iop.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) (limited to 'arch/m68k/mac') diff --git a/arch/m68k/mac/iop.c b/arch/m68k/mac/iop.c index d3775afb0f07..754f6478c30d 100644 --- a/arch/m68k/mac/iop.c +++ b/arch/m68k/mac/iop.c @@ -415,7 +415,8 @@ static void iop_handle_send(uint iop_num, uint chan) msg->status = IOP_MSGSTATUS_UNUSED; msg = msg->next; iop_send_queue[iop_num][chan] = msg; - if (msg) iop_do_send(msg); + if (msg && iop_readb(iop, IOP_ADDR_SEND_STATE + chan) == IOP_MSG_IDLE) + iop_do_send(msg); } /* @@ -489,16 +490,12 @@ int iop_send_message(uint iop_num, uint chan, void *privdata, if (!(q = iop_send_queue[iop_num][chan])) { iop_send_queue[iop_num][chan] = msg; + iop_do_send(msg); } else { while (q->next) q = q->next; q->next = msg; } - if (iop_readb(iop_base[iop_num], - IOP_ADDR_SEND_STATE + chan) == IOP_MSG_IDLE) { - iop_do_send(msg); - } - return 0; } -- cgit v1.2.3