target/linux/s3c24xx/patches-2.6.26/1058-fix-pcf50633-LOWBAT-kill-init.patch.patch

   1 From 6d3172ba9f1b4a650c8fdb3b6e11dc71852fe6d1 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-pcf50633-LOWBAT-kill-init.patch
   5
   6 ---
   7  drivers/i2c/chips/pcf50633.c |   56 ++++++++++++++++++++++++++++++++++++-----
   8  1 files changed, 49 insertions(+), 7 deletions(-)
   9
  10 diff --git a/drivers/i2c/chips/pcf50633.c b/drivers/i2c/chips/pcf50633.c
  11 index 0cf5e53..fc1262e 100644
  12 --- a/drivers/i2c/chips/pcf50633.c
  13 +++ b/drivers/i2c/chips/pcf50633.c
  14 @@ -690,8 +690,20 @@ static void pcf50633_work(struct work_struct *work)
  15                         if (pcf->onkey_seconds >=
  16                             pcf->pdata->onkey_seconds_sig_init) {
  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 +                                       DEBUGPC("SIGINT(init) ");
  32 +                                       kill_proc(1, SIGINT, 1);
  33 +                               }
  34                                 /* FIXME: what if userspace doesn't shut down? */
  35                         }
  36                         if (pcf->onkey_seconds >=
  37 @@ -790,11 +802,41 @@ static void pcf50633_work(struct work_struct *work)
  38         }
  39
  40         if (pcfirq[3] & (PCF50633_INT4_LOWBAT|PCF50633_INT4_LOWSYS)) {
  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, PCF50633_REG_MBCS1) &
  47 +                   (PCF50633_MBCS1_USBPRES | PCF50633_MBCS1_USBOK)) ==
  48 +                   (PCF50633_MBCS1_USBPRES | PCF50633_MBCS1_USBOK)) {
  49 +                       /*
  50 +                        * hey no need to freak out, we have some kind of
  51 +                        * valid charger power
  52 +                        */
  53 +                       DEBUGPC("(NO)BAT ");
  54 +               } else {
  55 +                       /* Really low battery voltage, we have 8 seconds left */
  56 +                       DEBUGPC("LOWBAT ");
  57 +                       /*
  58 +                        * currently Linux reacts badly to issuing a signal to
  59 +                        * PID #1 before init is started.  What happens is that
  60 +                        * the next kernel thread to start, which is the JFFS2
  61 +                        * Garbage collector in our case, gets the signal
  62 +                        * instead and proceeds to fail to fork -- which is
  63 +                        * very bad.  Therefore we confirm PID #1 exists
  64 +                        * before issuing SPIGPWR
  65 +                        */
  66 +                       if (find_task_by_pid(1)) {
  67 +                               apm_queue_event(APM_LOW_BATTERY);
  68 +                               DEBUGPC("SIGPWR(init) ");
  69 +                               kill_proc(1, SIGPWR, 1);
  70 +                       } else
  71 +                               /*
  72 +                                * well, our situation is like this:  we do not
  73 +                                * have any external power, we have a low
  74 +                                * battery and since PID #1 doesn't exist yet,
  75 +                                * we are early in the boot, likely before
  76 +                                * rootfs mount.  We should just call it a day
  77 +                                */
  78 +                               apm_queue_event(APM_CRITICAL_SUSPEND);
  79 +               }
  80 +
  81                 /* Tell PMU we are taking care of this */
  82                 reg_set_bit_mask(pcf, PCF50633_REG_OOCSHDWN,
  83                                  PCF50633_OOCSHDWN_TOTRST,
  84 --
  85 1.5.6.3
  86