target/linux/s3c24xx/patches-2.6.26/1057-fix-pcf50606-LOWBAT-kill-init.patch.patch

   1 From 835002d2e751c0d35b744ceec5bef726b9778b7b Mon Sep 17 00:00:00 2001
   2 From: mokopatches <mokopatches@openmoko.org>
   3 Date: Fri, 25 Jul 2008 22:21:25 +0100
   4 Subject: [PATCH] fix-pcf50606-LOWBAT-kill-init.patch
   5
   6 ---
   7  drivers/i2c/chips/pcf50606.c |   53 ++++++++++++++++++++++++++++++++++++-----
   8  1 files changed, 46 insertions(+), 7 deletions(-)
   9
  10 diff --git a/drivers/i2c/chips/pcf50606.c b/drivers/i2c/chips/pcf50606.c
  11 index b530583..a1c92d3 100644
  12 --- a/drivers/i2c/chips/pcf50606.c
  13 +++ b/drivers/i2c/chips/pcf50606.c
  14 @@ -654,8 +654,20 @@ static void pcf50606_work(struct work_struct *work)
  15                         if (pcf->onkey_seconds >=
  16                             pcf->pdata->onkey_seconds_required) {
  17                                 /* Ask init to do 'ctrlaltdel' */
  18 -                               DEBUGPC("SIGINT(init) ");
  19 -                               kill_proc(1, SIGINT, 1);
  20 +                               /*
  21 +                                * currently Linux reacts badly to issuing a
  22 +                                * signal to PID #1 before init is started.
  23 +                                * What happens is that the next kernel thread
  24 +                                * to start, which is the JFFS2 Garbage
  25 +                                * collector in our case, gets the signal
  26 +                                * instead and proceeds to fail to fork --
  27 +                                * which is very bad.  Therefore we confirm
  28 +                                * PID #1 exists before issuing the signal
  29 +                                */
  30 +                               if (find_task_by_pid(1)) {
  31 +                                       kill_proc(1, SIGINT, 1);
  32 +                                       DEBUGPC("SIGINT(init) ");
  33 +                               }
  34                                 /* FIXME: what to do if userspace doesn't
  35                                  * shut down? Do we want to force it? */
  36                         }
  37 @@ -749,11 +761,38 @@ static void pcf50606_work(struct work_struct *work)
  38         }
  39         /* FIXME: TSCPRES */
  40         if (pcfirq[2] & PCF50606_INT3_LOWBAT) {
  41 -               /* Really low battery voltage, we have 8 seconds left */
  42 -               DEBUGPC("LOWBAT ");
  43 -               apm_queue_event(APM_LOW_BATTERY);
  44 -               DEBUGPC("SIGPWR(init) ");
  45 -               kill_proc(1, SIGPWR, 1);
  46 +               if (__reg_read(pcf, PCF50606_REG_OOCS) & PCF50606_OOCS_EXTON) {
  47 +                       /*
  48 +                        * hey no need to freak out, we have some kind of
  49 +                        * valid charger power
  50 +                        */
  51 +                       DEBUGPC("(NO)BAT ");
  52 +               } else {
  53 +                       /* Really low battery voltage, we have 8 seconds left */
  54 +                       DEBUGPC("LOWBAT ");
  55 +                       /*
  56 +                        * currently Linux reacts badly to issuing a signal to
  57 +                        * PID #1 before init is started.  What happens is that
  58 +                        * the next kernel thread to start, which is the JFFS2
  59 +                        * Garbage collector in our case, gets the signal
  60 +                        * instead and proceeds to fail to fork -- which is
  61 +                        * very bad.  Therefore we confirm PID #1 exists
  62 +                        * before issuing SPIGPWR
  63 +                        */
  64 +                       if (find_task_by_pid(1)) {
  65 +                               apm_queue_event(APM_LOW_BATTERY);
  66 +                               DEBUGPC("SIGPWR(init) ");
  67 +                               kill_proc(1, SIGPWR, 1);
  68 +                       } else
  69 +                               /*
  70 +                                * well, our situation is like this:  we do not
  71 +                                * have any external power, we have a low
  72 +                                * battery and since PID #1 doesn't exist yet,
  73 +                                * we are early in the boot, likely before
  74 +                                * rootfs mount.  We should just call it a day
  75 +                                */
  76 +                               apm_queue_event(APM_CRITICAL_SUSPEND);
  77 +               }
  78                 /* Tell PMU we are taking care of this */
  79                 reg_set_bit_mask(pcf, PCF50606_REG_OOCC1,
  80                                  PCF50606_OOCC1_TOTRST,
  81 --
  82 1.5.6.3
  83