Messages in this thread | | | Date | Mon, 23 Jan 2006 09:57:00 +0000 | From | Russell King <> | Subject | Re: [PATCH] serial: serial_txx9 driver update |
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On Mon, Jan 23, 2006 at 03:05:02PM +0900, Atsushi Nemoto wrote: > - if (disr & TXX9_SIDISR_UOER) > + if (disr & TXX9_SIDISR_UOER) { > up->port.icount.overrun++; > + /* > + * The receiver read buffer still hold > + * a char which caused overrun. > + * Ignore next char by adding RFDN_MASK > + * to ignore_status_mask temporarily. > + */ > + next_ignore_status_mask |= > + TXX9_SIDISR_RFDN_MASK; > + }
I'm not sure what you mean here.
If we successfully received the string ABCDEFGH, and the next character to be received (I) causes an overrun condition, what happens in the case that overruns are not ignored?
Will you read ABCDEFG without any errors from the UART, and then H with an overrun error? If so, you should pass to the TTY layer ABCDEFGH and then a NUL character with TTY_OVERRUN set. Note that uart_insert_char() does this for you.
Alternatively, the UART may give you: ABCDEFGI where I is marked as an overrun error. In this case, you want to pass to the TTY layer ABCDEFG, then a NUL character with TTY_OVERRUN set, then I.
If overruns are ignored, you merely omit to insert the NUL character with TTY_OVERRUN set.
-- 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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