From: Pavel Machek <pavel@ucw.cz>
To correctly stop all DMA activity, make the boot kernel put all devices
into suspend state before entering the resume kernel image.
---
25-akpm/kernel/power/swsusp.c | 39 +++++++++------------------------------
1 files changed, 9 insertions(+), 30 deletions(-)
diff -puN kernel/power/swsusp.c~swsusp-stop-DMA-on-resume kernel/power/swsusp.c
--- 25/kernel/power/swsusp.c~swsusp-stop-DMA-on-resume Tue Jan 20 15:08:58 2004
+++ 25-akpm/kernel/power/swsusp.c Tue Jan 20 15:08:58 2004
@@ -488,33 +488,6 @@ static void free_some_memory(void)
printk("|\n");
}
-/* Make disk drivers accept operations, again */
-static void drivers_unsuspend(void)
-{
- device_resume();
-}
-
-/* Called from process context */
-static int drivers_suspend(void)
-{
- return device_suspend(4);
-}
-
-#define RESUME_PHASE1 1 /* Called from interrupts disabled */
-#define RESUME_PHASE2 2 /* Called with interrupts enabled */
-#define RESUME_ALL_PHASES (RESUME_PHASE1 | RESUME_PHASE2)
-static void drivers_resume(int flags)
-{
- if (flags & RESUME_PHASE1) {
- device_resume();
- }
- if (flags & RESUME_PHASE2) {
-#ifdef SUSPEND_CONSOLE
- update_screen(fg_console); /* Hmm, is this the problem? */
-#endif
- }
-}
-
static int suspend_prepare_image(void)
{
struct sysinfo i;
@@ -569,7 +542,7 @@ static int suspend_prepare_image(void)
static void suspend_save_image(void)
{
- drivers_unsuspend();
+ device_resume();
lock_swapdevices();
write_suspend_image();
@@ -615,6 +588,7 @@ void do_magic_resume_1(void)
mb();
spin_lock_irq(&suspend_pagedir_lock); /* Done to disable interrupts */
+ device_power_down(4);
PRINTK( "Waiting for DMAs to settle down...\n");
mdelay(1000); /* We do not want some readahead with DMA to corrupt our memory, right?
Do it with disabled interrupts for best effect. That way, if some
@@ -630,8 +604,10 @@ void do_magic_resume_2(void)
PRINTK( "Freeing prev allocated pagedir\n" );
free_suspend_pagedir((unsigned long) pagedir_save);
+ device_power_up();
spin_unlock_irq(&suspend_pagedir_lock);
- drivers_resume(RESUME_ALL_PHASES);
+ device_resume();
+ update_screen(fg_console); /* Hmm, is this the problem? */
PRINTK( "Fixing swap signatures... " );
mark_swapfiles(((swp_entry_t) {0}), MARK_SWAP_RESUME);
@@ -672,7 +648,9 @@ void do_magic_suspend_2(void)
{
int is_problem;
read_swapfiles();
+ device_power_down(4);
is_problem = suspend_prepare_image();
+ device_power_up();
spin_unlock_irq(&suspend_pagedir_lock);
if (!is_problem) {
kernel_fpu_end(); /* save_processor_state() does kernel_fpu_begin, and we need to revert it in order to pass in_atomic() checks */
@@ -716,7 +694,7 @@ static void do_software_suspend(void)
blk_run_queues();
/* Save state of all device drivers, and stop them. */
- if(drivers_suspend()==0)
+ if ((res = device_suspend(4))==0)
/* If stopping device drivers worked, we proceed basically into
* suspend_save_image.
*
@@ -1091,6 +1069,7 @@ static int __init software_resume(void)
printk( "resuming from %s\n", resume_file);
if (read_suspend_image(resume_file, 0))
goto read_failure;
+ device_suspend(4);
do_magic(1);
panic("This never returns");
_