From 458c77f3de0edc8a2df1f54ac641823ccbd3ff56 Mon Sep 17 00:00:00 2001 From: Finn Thain Date: Tue, 15 Jan 2019 15:18:56 +1100 Subject: [PATCH] macintosh/via-cuda: Don't rely on Cuda to end a transfer Certain Cuda transfers have to be ended by the driver. According to Apple's open source Cuda driver, as found in mkLinux and XNU, this applies to any "open ended request such as PRAM read". This fixes an infinite polling loop in cuda_pram_read_byte(). Tested-by: Stan Johnson Signed-off-by: Finn Thain Signed-off-by: Greg Kroah-Hartman --- drivers/macintosh/via-cuda.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/macintosh/via-cuda.c b/drivers/macintosh/via-cuda.c index bbec6ac0a966..3581abfb0c6a 100644 --- a/drivers/macintosh/via-cuda.c +++ b/drivers/macintosh/via-cuda.c @@ -569,6 +569,7 @@ cuda_interrupt(int irq, void *arg) unsigned char ibuf[16]; int ibuf_len = 0; int complete = 0; + bool full; spin_lock_irqsave(&cuda_lock, flags); @@ -656,12 +657,13 @@ idle_state: break; case reading: - if (reading_reply ? ARRAY_FULL(current_req->reply, reply_ptr) - : ARRAY_FULL(cuda_rbuf, reply_ptr)) + full = reading_reply ? ARRAY_FULL(current_req->reply, reply_ptr) + : ARRAY_FULL(cuda_rbuf, reply_ptr); + if (full) (void)in_8(&via[SR]); else *reply_ptr++ = in_8(&via[SR]); - if (!TREQ_asserted(status)) { + if (!TREQ_asserted(status) || full) { if (mcu_is_egret) assert_TACK(); /* that's all folks */ -- 2.30.2