From 43a9caa2214faffaa1fd5ce1730063f9959a8ce8 Mon Sep 17 00:00:00 2001 From: Nathan Binkert Date: Tue, 29 Mar 2005 07:55:44 -0500 Subject: expose variables for number of global events per simulated second, millisecond, microsecond, etc. so that the user can explicitly convert between system ticks and time and know what sorts of expensive operations are being used for that conversion. arch/alpha/alpha_tru64_process.cc: arch/alpha/pseudo_inst.cc: dev/etherdump.cc: dev/etherlink.cc: dev/ns_gige.cc: dev/sinic.cc: dev/tsunami_io.cc: dev/uart.cc: sim/stat_control.cc: sim/syscall_emul.hh: Use the new variables for getting the event clock dev/etherdump.hh: delete variables that are no longer needed. --HG-- extra : convert_revision : d95fc7d44909443e1b7952a24ef822ef051c7cf2 --- dev/uart.cc | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) (limited to 'dev/uart.cc') diff --git a/dev/uart.cc b/dev/uart.cc index 3c4ab6d04..caa169a2e 100644 --- a/dev/uart.cc +++ b/dev/uart.cc @@ -73,17 +73,28 @@ Uart::IntrEvent::process() } +/* The linux serial driver (8250.c about line 1182) loops reading from + * the device until the device reports it has no more data to + * read. After a maximum of 255 iterations the code prints "serial8250 + * too much work for irq X," and breaks out of the loop. Since the + * simulated system is so much slower than the actual system, if a + * user is typing on the keyboard it is very easy for them to provide + * input at a fast enough rate to not allow the loop to exit and thus + * the error to be printed. This magic number provides a delay between + * the time the UART receives a character to send to the simulated + * system and the time it actually notifies the system it has a + * character to send to alleviate this problem. --Ali + */ void Uart::IntrEvent::scheduleIntr() { + static const Tick interval = (Tick)((Clock::Float::s / 2e9) * 450); DPRINTF(Uart, "Scheduling IER interrupt for %#x, at cycle %lld\n", intrBit, - curTick + (ticksPerSecond/2000) * 350); + curTick + interval); if (!scheduled()) - /* @todo Make this cleaner, will be much easier with - * nanosecond time everywhere. Hint hint Nate. */ - schedule(curTick + (ticksPerSecond/2000000000) * 450); + schedule(curTick + interval); else - reschedule(curTick + (ticksPerSecond/2000000000) * 450); + reschedule(curTick + interval); } Uart::Uart(const string &name, SimConsole *c, MemoryController *mmu, Addr a, -- cgit v1.2.3