Openmoko Bug #2309: hangs during resume after printing GSTATUS4

[Openmoko Public Trac]

#2309: hangs during resume after printing GSTATUS4
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 Reporter:  lindi   |          Owner:  openmoko-kernel      
     Type:  defect  |         Status:  new                  
 Priority:  normal  |      Milestone:                       
Component:  kernel  |        Version:                       
 Severity:  normal  |       Keywords:  resume suspend kernel
 Haspatch:  0       |      Blockedby:                       
Estimated:          |    Patchreview:                       
 Blocking:          |   Reproducible:  rarely               
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Comment(by lindi):

 I made some progress:

 11 days ago I modified my u-boot to turn the vibrator on very early in
 resume:

 {{{
 diff --git a/cpu/arm920t/start.S b/cpu/arm920t/start.S
 index 93bf7e9..82c2047 100644
 --- a/cpu/arm920t/start.S
 +++ b/cpu/arm920t/start.S
 @@ -160,6 +160,12 @@ start_code:
         orr     r0,r0,#0xd3
         msr     cpsr,r0

 +       ldr     r0, =0x56000014
 +       ldr     r1, [r0]
 +       orr     r1, r1, #0x8 /* vibrator on */
 +       bic     r1, r1, #0x4 /* aux off */
 +       str     r1, [r0]
 +
         /* in case we run from the s3c24xx NAND stepping stone, the
 symbols
          * for LED support are in lib_arm/board.o, i.e. outside of the
          * steppingstone */


 }}}

 This causes the vibrator to run for about a second during boot and maybe
 about 20 ms during normal resume.

 This morning I noticed that the phone had not woken up from suspend
 properly and the vibrator was constantly on. I think this proves that the
 phone suspends properly and the CPU wakes from suspend due to RTC
 interrupt properly but something goes wrong somewhere between the first
 u-boot instructions and linux resume code.

 Unfortunately I really did not have the time to debug this with JTAG.
 Since I don't know what kind of permanent damage would be caused if I left
 the vibrator running for hours I decided to just remove the battery.
 Anyways, I hope that next time this occurs at a more suitable time so that
 I can attach the debug board and see what's going on :-)

-- 
Ticket URL: <https://docs.openmoko.org/trac/ticket/2309#comment:13>
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