Messages in this thread | | | Date | Fri, 18 Aug 2006 22:02:17 +0100 | From | Russell King <> | Subject | Re: Serial issue |
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On Fri, Aug 18, 2006 at 04:54:13PM -0400, Lee Revell wrote: > On Fri, 2006-08-18 at 21:34 +0100, Russell King wrote: > > On Fri, Aug 18, 2006 at 04:28:36PM -0400, Lee Revell wrote: > > > On Fri, 2006-08-18 at 16:25 -0400, Mark Hounschell wrote: > > > > Take it from someone who actually still uses dumb terminals every day, > > > > any thing over 9600 baud still requires some kind of flow control for > > > > reliable consistent operation. Software (Xon/Xoff) and or hardware > > > > (RTS/RTS/DTE) flow control. > > > > > > > > > > Any idea why the serial console does not work at all with flow control > > > enabled (regardless of whether the host runs Linux or another OS)? > > > > I use serial console with flow control and haven't seen any problems. > > > > Can you describe your issue with more detail? > > > > What actions are required to get this "does not work at all" state? > > > > Are you passing a kernel parameter to enable flow control? > > > > Are you saying that you get kernel messages if flow control is disabled, > > but if you subsequently enable flow control, and provoke a kernel message, > > you don't see any messages? When you re-disable flow control, you do? > > > > I believe the flow control problem is due to my cable. > > Anyway I don't want to confuse the issue: the problem that I want to > solve (or at least explain) is that while the serial console works with > the host serial port in both interrupt and polled mode, kermit file > transfers only work in polled mode ("setserial /dev/ttyS0 irq 0").
If you're talking about sending via a polled port, the average data rate is probably slow enough that the receiving side can keep up. But in interrupt mode, it's probably a stream of characters at the specified baud rate, which results in lost characters.
That explaination doesn't resolve the receiving via a polled port though.
-- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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