Messages in this thread |  | | | Subject | Serial: bug in 8250.c when handling PCI or other level triggers | | From | Alan Cox <> | | Date | Wed, 14 Dec 2005 15:23:23 +0000 |
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The receive_chars function is designed to handle the case where the port is jammed full on by aborting after 256 characters in one IRQ. Unfortunately the author of this code forgot that some systems are level triggered. On these systems the IRQ simply gets invoked again and the count loop just makes the problem take longer to clear.
In the non level case it appears that a jam could leave the IRQ jammed forever and ignored - the remaining bytes never appearing.
As far as I can see the code would actually need to clear the interrupt enable and then restore it on a timer event or similar in order to get the intended effect.
Alan
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