Messages in this thread | | | Date | Mon, 6 Jun 2005 09:03:50 -0600 | From | Jim Ramsay <> | Subject | Re: Bug in 8520.c - port.type not set for serial console |
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On 5/31/05, Bjorn Helgaas <bjorn.helgaas@hp.com> wrote: > On Monday 30 May 2005 4:38 pm, Jim Ramsay wrote: > > I am attempting to get the 8520.c driver's serial console working with > > a 16550A UART implementation, and have run into what I consider to be > > a bug: In short, the proper 'port.type' for this serial port is not > > set until the module init (serial8250_init) is called, so the FCR is > > set incorrectly during serial8250_console_init for any port type which > > is different than UNKNOWN. > > > > The exact problem is that the FCR is being set to '0x0' for a port > > type of 'UNKNOWN', when for my specific 16550A, it should be set to > > '0xC1' - and this makes my screen fill with empty characters instead > > of the printk output I need. > > Shouldn't a 16550A UART work correctly with FCR==0x0, i.e., with FIFOs > disabled? Is your UART broken?
That's a good question. I'll me looking into this in the near future.
> Serial console output is always polled, one character at a time, so > you shouldn't need FIFOs until later.
True, as long as it works that way... so far I haven't seen it actually function properly yet with FCR set to 0.
-- Jim Ramsay "Me fail English? That's unpossible!" - 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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