From 86be80086fba1f2f22c9d5ed28a6ea256541cfec Mon Sep 17 00:00:00 2001 From: Roger Pau Monne Date: Wed, 25 Sep 2013 16:57:20 +0200 Subject: [PATCH 3/3] ns8250: switch the putc loop to use a time based timeout Additionally, we have to move one printf in hvm.c so that it is not printed on resume, because it happens before we can set the vcpu_info area, and trying to read the clock without the vcpu_info are set would result in a panic. --- sys/dev/uart/uart_dev_ns8250.c | 15 ++++++++++----- sys/x86/xen/hvm.c | 3 +-- 2 files changed, 11 insertions(+), 7 deletions(-) diff --git a/sys/dev/uart/uart_dev_ns8250.c b/sys/dev/uart/uart_dev_ns8250.c index 211d113..53c1e89 100644 --- a/sys/dev/uart/uart_dev_ns8250.c +++ b/sys/dev/uart/uart_dev_ns8250.c @@ -54,6 +54,9 @@ __FBSDID("$FreeBSD$"); #define DEFAULT_RCLK 1843200 +/* Max wait time in microseconds */ +#define DEFAULT_WAIT 10 + static int broken_txfifo = 0; SYSCTL_INT(_hw, OID_AUTO, broken_txfifo, CTLFLAG_RW | CTLFLAG_TUN, &broken_txfifo, 0, "UART FIFO has QEMU emulation bug"); @@ -314,15 +317,17 @@ ns8250_term(struct uart_bas *bas) static void ns8250_putc(struct uart_bas *bas, int c) { - int limit; + sbintime_t end; - limit = 250000; - while ((uart_getreg(bas, REG_LSR) & LSR_THRE) == 0 && --limit) + end = getsbinuptime() + DEFAULT_WAIT * SBT_1US; + while ((uart_getreg(bas, REG_LSR) & LSR_THRE) == 0 && + (end > getsbinuptime())) DELAY(4); uart_setreg(bas, REG_DATA, c); uart_barrier(bas); - limit = 250000; - while ((uart_getreg(bas, REG_LSR) & LSR_TEMT) == 0 && --limit) + end = getsbinuptime() + DEFAULT_WAIT * SBT_1US; + while ((uart_getreg(bas, REG_LSR) & LSR_TEMT) == 0 && + (end > getsbinuptime())) DELAY(4); } diff --git a/sys/x86/xen/hvm.c b/sys/x86/xen/hvm.c index 467c9e3..79a7e52 100644 --- a/sys/x86/xen/hvm.c +++ b/sys/x86/xen/hvm.c @@ -671,8 +671,6 @@ xen_hvm_disable_emulated_devices(void) if (inw(XEN_MAGIC_IOPORT) != XMI_MAGIC) return; - if (bootverbose) - printf("XEN: Disabling emulated block and network devices\n"); outw(XEN_MAGIC_IOPORT, XMI_UNPLUG_IDE_DISKS|XMI_UNPLUG_NICS); } @@ -695,6 +693,7 @@ xen_hvm_init(enum xen_hvm_init_type init_type) setup_xen_features(); cpu_ops.cpu_init = xen_hvm_cpu_init; cpu_ops.cpu_resume = xen_hvm_cpu_resume; + printf("XEN: Disabling emulated block and network devices\n"); break; case XEN_HVM_INIT_RESUME: if (error != 0) -- 1.7.7.5 (Apple Git-26)