diff options
Diffstat (limited to 'arch/i386/kernel/apm.c')
| -rw-r--r-- | arch/i386/kernel/apm.c | 97 |
1 files changed, 36 insertions, 61 deletions
diff --git a/arch/i386/kernel/apm.c b/arch/i386/kernel/apm.c index 1e60acbed3c..2d793d4aef1 100644 --- a/arch/i386/kernel/apm.c +++ b/arch/i386/kernel/apm.c @@ -303,17 +303,6 @@ extern int (*console_blank_hook)(int); #include "apm.h" /* - * Define to make all _set_limit calls use 64k limits. The APM 1.1 BIOS is - * supposed to provide limit information that it recognizes. Many machines - * do this correctly, but many others do not restrict themselves to their - * claimed limit. When this happens, they will cause a segmentation - * violation in the kernel at boot time. Most BIOS's, however, will - * respect a 64k limit, so we use that. If you want to be pedantic and - * hold your BIOS to its claims, then undefine this. - */ -#define APM_RELAX_SEGMENTS - -/* * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend. * This patched by Chad Miller <cmiller@surfsouth.com>, original code by * David Chen <chen@ctpa04.mit.edu> @@ -1075,22 +1064,23 @@ static int apm_engage_power_management(u_short device, int enable) static int apm_console_blank(int blank) { - int error; - u_short state; + int error, i; + u_short state; + static const u_short dev[3] = { 0x100, 0x1FF, 0x101 }; state = blank ? APM_STATE_STANDBY : APM_STATE_READY; - /* Blank the first display device */ - error = set_power_state(0x100, state); - if ((error != APM_SUCCESS) && (error != APM_NO_ERROR)) { - /* try to blank them all instead */ - error = set_power_state(0x1ff, state); - if ((error != APM_SUCCESS) && (error != APM_NO_ERROR)) - /* try to blank device one instead */ - error = set_power_state(0x101, state); + + for (i = 0; i < ARRAY_SIZE(dev); i++) { + error = set_power_state(dev[i], state); + + if ((error == APM_SUCCESS) || (error == APM_NO_ERROR)) + return 1; + + if (error == APM_NOT_ENGAGED) + break; } - if ((error == APM_SUCCESS) || (error == APM_NO_ERROR)) - return 1; - if (error == APM_NOT_ENGAGED) { + + if (error == APM_NOT_ENGAGED && state != APM_STATE_READY) { static int tried; int eng_error; if (tried++ == 0) { @@ -2233,8 +2223,8 @@ static struct dmi_system_id __initdata apm_dmi_table[] = { static int __init apm_init(void) { struct proc_dir_entry *apm_proc; + struct desc_struct *gdt; int ret; - int i; dmi_check_system(apm_dmi_table); @@ -2312,45 +2302,30 @@ static int __init apm_init(void) set_base(bad_bios_desc, __va((unsigned long)0x40 << 4)); _set_limit((char *)&bad_bios_desc, 4095 - (0x40 << 4)); + /* + * Set up the long jump entry point to the APM BIOS, which is called + * from inline assembly. + */ apm_bios_entry.offset = apm_info.bios.offset; apm_bios_entry.segment = APM_CS; - for (i = 0; i < NR_CPUS; i++) { - struct desc_struct *gdt = get_cpu_gdt_table(i); - set_base(gdt[APM_CS >> 3], - __va((unsigned long)apm_info.bios.cseg << 4)); - set_base(gdt[APM_CS_16 >> 3], - __va((unsigned long)apm_info.bios.cseg_16 << 4)); - set_base(gdt[APM_DS >> 3], - __va((unsigned long)apm_info.bios.dseg << 4)); -#ifndef APM_RELAX_SEGMENTS - if (apm_info.bios.version == 0x100) { -#endif - /* For ASUS motherboard, Award BIOS rev 110 (and others?) */ - _set_limit((char *)&gdt[APM_CS >> 3], 64 * 1024 - 1); - /* For some unknown machine. */ - _set_limit((char *)&gdt[APM_CS_16 >> 3], 64 * 1024 - 1); - /* For the DEC Hinote Ultra CT475 (and others?) */ - _set_limit((char *)&gdt[APM_DS >> 3], 64 * 1024 - 1); -#ifndef APM_RELAX_SEGMENTS - } else { - _set_limit((char *)&gdt[APM_CS >> 3], - (apm_info.bios.cseg_len - 1) & 0xffff); - _set_limit((char *)&gdt[APM_CS_16 >> 3], - (apm_info.bios.cseg_16_len - 1) & 0xffff); - _set_limit((char *)&gdt[APM_DS >> 3], - (apm_info.bios.dseg_len - 1) & 0xffff); - /* workaround for broken BIOSes */ - if (apm_info.bios.cseg_len <= apm_info.bios.offset) - _set_limit((char *)&gdt[APM_CS >> 3], 64 * 1024 -1); - if (apm_info.bios.dseg_len <= 0x40) { /* 0x40 * 4kB == 64kB */ - /* for the BIOS that assumes granularity = 1 */ - gdt[APM_DS >> 3].b |= 0x800000; - printk(KERN_NOTICE "apm: we set the granularity of dseg.\n"); - } - } -#endif - } + /* + * The APM 1.1 BIOS is supposed to provide limit information that it + * recognizes. Many machines do this correctly, but many others do + * not restrict themselves to their claimed limit. When this happens, + * they will cause a segmentation violation in the kernel at boot time. + * Most BIOS's, however, will respect a 64k limit, so we use that. + * + * Note we only set APM segments on CPU zero, since we pin the APM + * code to that CPU. + */ + gdt = get_cpu_gdt_table(0); + set_base(gdt[APM_CS >> 3], + __va((unsigned long)apm_info.bios.cseg << 4)); + set_base(gdt[APM_CS_16 >> 3], + __va((unsigned long)apm_info.bios.cseg_16 << 4)); + set_base(gdt[APM_DS >> 3], + __va((unsigned long)apm_info.bios.dseg << 4)); apm_proc = create_proc_info_entry("apm", 0, NULL, apm_get_info); if (apm_proc) |