From: Finn Thain Date: Sat, 30 May 2020 23:12:13 +0000 (+1000) Subject: m68k: mac: Don't send IOP message until channel is idle X-Git-Tag: v4.14.194~173 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=275ae397e4ef7474d45075813b4383a736443d7e;p=users%2Fdwmw2%2Flinux.git m68k: mac: Don't send IOP message until channel is idle [ Upstream commit aeb445bf2194d83e12e85bf5c65baaf1f093bd8f ] 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 Signed-off-by: Sasha Levin --- diff --git a/arch/m68k/mac/iop.c b/arch/m68k/mac/iop.c index 4c1e606e7d03b..fb61af5ac4ab8 100644 --- a/arch/m68k/mac/iop.c +++ b/arch/m68k/mac/iop.c @@ -416,7 +416,8 @@ 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); } /* @@ -490,16 +491,12 @@ 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; }