d5a9597d69
Today, all possible serial lines (ssl*=) as well as all possible consoles (con*=) each share a single interrupt (with a fixed number) with others of the same type. Now, if you have two lines, say ssl0 and ssl1, and one of them is connected to an fd you cannot read (e.g. a file), but the other gets a read interrupt, then both of them get the interrupt since it's shared. Then, the read() call will return EOF, since it's a file being written and there's nothing to read (at least not at the current offset, at the end). Unfortunately, this is treated as a read error, and we close this line, losing all the possible output. It might be possible to work around this and make the IRQ sharing work, however, now that we have dynamically allocated IRQs that are easy to use, simply use that to achieve separating between the events; then there's no interrupt for that line and we never attempt the read in the first place, thus not closing the line. This manifested itself in the wifi hostap/hwsim tests where the parallel script communicates via one serial console and the kernel messages go to another (a file) and sending data on the communication console caused the kernel messages to stop flowing into the file. Reported-by: Jouni Malinen <j@w1.fi> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Acked-By: anton ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at>
40 lines
828 B
C
40 lines
828 B
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __UM_IRQ_H
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#define __UM_IRQ_H
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#define TIMER_IRQ 0
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#define UMN_IRQ 1
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#define UBD_IRQ 2
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#define UM_ETH_IRQ 3
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#define ACCEPT_IRQ 4
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#define MCONSOLE_IRQ 5
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#define WINCH_IRQ 6
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#define SIGIO_WRITE_IRQ 7
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#define TELNETD_IRQ 8
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#define XTERM_IRQ 9
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#define RANDOM_IRQ 10
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#ifdef CONFIG_UML_NET_VECTOR
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#define VECTOR_BASE_IRQ (RANDOM_IRQ + 1)
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#define VECTOR_IRQ_SPACE 8
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#define UM_FIRST_DYN_IRQ (VECTOR_IRQ_SPACE + VECTOR_BASE_IRQ)
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#else
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#define UM_FIRST_DYN_IRQ (RANDOM_IRQ + 1)
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#endif
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#define UM_LAST_SIGNAL_IRQ 64
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/* If we have (simulated) PCI MSI, allow 64 more interrupt numbers for it */
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#ifdef CONFIG_PCI_MSI
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#define NR_IRQS (UM_LAST_SIGNAL_IRQ + 64)
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#else
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#define NR_IRQS UM_LAST_SIGNAL_IRQ
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#endif /* CONFIG_PCI_MSI */
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#include <asm-generic/irq.h>
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#endif
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