From mboxrd@z Thu Jan 1 00:00:00 1970 Message-Id: <200007301300.OAA07050@hyperion.valhalla.net> Date: Sun, 30 Jul 2000 14:01:19 +0100 Subject: Re: Stealth port problems From: "Iain Sandoe" To: Takashi Oe CC: linuxppc-dev@lists.linuxppc.org Mime-version: 1.0 Content-type: text/plain; charset="US-ASCII" Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: On Sun, Jul 30, 2000, Takashi Oe wrote: > On Sun, 30 Jul 2000, Iain Sandoe wrote: > > [...] >> The RX buffer in an 85230 (which is actually the chip - IIRC - an enhanced >> 8530) is 8 characters deep > > Ok, this is a news to me. I'm certain that SCC on oldworld pmacs is > 85C30. When did the change to 85230 occur? If I remember correctly, > some DMA setup codes in macserial.c need to know about it if it's dealing > with 85230 rather than 85C30. OK - I don't know for certain - but the code refers to an "ESCC" which is the name of the 85230 - the 8530 should just be called "SCC". >> - so any more that about 700 us IRQ block will >> cause a drop out at 115200 continuous... > > With DMA, this is a non-issue as far as serial driver is concerned. This is, of course, true - unless something blocks for long enough to prevent the IRQ that indicates end-of-dma transfer (assuming there is one). Iain, ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/