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| author |   Finn Thain <fthain@telegraphics.com.au> | 2020-05-31 09:12:13 +1000 |
|---|---|---|
| committer |   Geert Uytterhoeven <geert@linux-m68k.org> | 2020-07-13 11:39:13 +0200 |
| commit | aeb445bf2194d83e12e85bf5c65baaf1f093bd8f (patch) | |
| tree | d74b3c152f2cf88c6c9275da2e885e5f3c077dc6 /arch/m68k/mac | |
| parent | m68k: atari: Annotate dummy read in ROM port IO code as __maybe_unused (diff) | |
| download | linux-dev-aeb445bf2194d83e12e85bf5c65baaf1f093bd8f.tar.xz linux-dev-aeb445bf2194d83e12e85bf5c65baaf1f093bd8f.zip | |
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 <fthain@telegraphics.com.au>
Tested-by: Stan Johnson <userm57@yahoo.com>
Cc: Joshua Thompson <funaho@jurai.org>
Link: https://lore.kernel.org/r/6d667c39e53865661fa5a48f16829d18ed8abe54.1590880333.git.fthain@telegraphics.com.au
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Diffstat (limited to 'arch/m68k/mac')
| -rw-r--r-- | arch/m68k/mac/iop.c | 9 |
1 files changed, 3 insertions, 6 deletions
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; } |