[PATCH 1/1] UBUNTU: SAUCE: S3 early resume debug via keyboard LEDs

[Colin Ian King]

On Mon, 2011-05-23 at 16:29 -0700, John Johansen wrote:
> On 05/23/2011 07:06 AM, Colin King wrote:
> > From: Colin Ian King <colin.king at canonical.com>
> > 
> > Add support to debug S3 early resume by flashing the keyboard
> > LEDs three times in the realmode path.   This is useful to allow
> > one to determine if S3 hangs occur in the BIOS or during the early
> > resume phase.
> > 
> > Add kernel parameter acpi_sleep=s3_leds to enable the s3 debugging
> > option.  This can also be enabled by writing 8 to
> > /proc/sys/kernel/acpi_video_flags.
> > 
> > Signed-off-by: Colin Ian King <colin.king at canonical.com>
> > ---
> >  Documentation/kernel-parameters.txt      |    5 ++++-
> >  arch/x86/kernel/acpi/realmode/wakemain.c |   27 +++++++++++++++++++++++++++
> >  arch/x86/kernel/acpi/sleep.c             |    2 ++
> >  3 files changed, 33 insertions(+), 1 deletions(-)
> > 
> > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
> > index cc85a92..9f36ff4 100644
> > --- a/Documentation/kernel-parameters.txt
> > +++ b/Documentation/kernel-parameters.txt
> > @@ -244,12 +244,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
> >  			For broken nForce2 BIOS resulting in XT-PIC timer.
> >  
> >  	acpi_sleep=	[HW,ACPI] Sleep options
> > -			Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig,
> > +			Format: { s3_bios, s3_mode, s3_beep, s3_leds, s4_nohwsig,
> >  				  old_ordering, s4_nonvs, sci_force_enable }
> >  			See Documentation/power/video.txt for information on
> >  			s3_bios and s3_mode.
> >  			s3_beep is for debugging; it makes the PC's speaker beep
> >  			as soon as the kernel's real-mode entry point is called.
> > +			s3_leds is for debugging; it flashes the keyboard LEDs
> > +			3 times as soon as the kernel's real-mode entry point is
> > +			called.
> >  			s4_nohwsig prevents ACPI hardware signature from being
> >  			used during resume from hibernation.
> >  			old_ordering causes the ACPI 1.0 ordering of the _PTS
> > diff --git a/arch/x86/kernel/acpi/realmode/wakemain.c b/arch/x86/kernel/acpi/realmode/wakemain.c
> > index 883962d..1d108be 100644
> > --- a/arch/x86/kernel/acpi/realmode/wakemain.c
> > +++ b/arch/x86/kernel/acpi/realmode/wakemain.c
> > @@ -61,6 +61,30 @@ static void send_morse(const char *pattern)
> >  	}
> >  }
> >  
> > +#define I8042_STATUS_REG	0x64
> > +#define I8042_DATA_REG		0x60
> > +#define I8042_SET_LED_BITS	0xed
> > +#define I8042_STR_IBF		0x02
> > +
> > +static void flash_keyboard_leds(void)
> > +{
> > +	int i;
> > +	unsigned char leds = 7;
> > +
> > +	/* Flash keyboard LEDs 3 times */
> > +	for (i = 0; i < 6; i++) {
> > +		while (inb(I8042_STATUS_REG) & I8042_STR_IBF)
> > +			;
> > +		outb(I8042_SET_LED_BITS, I8042_DATA_REG);
> > +		while (inb(I8042_STATUS_REG) & I8042_STR_IBF)
> > +			;
> > +		outb(leds, I8042_DATA_REG);
> > +		leds ^= 7;
> > +		udelay(500000);
> > +	}
> > +}
> > +
> > +
> >  void main(void)
> >  {
> >  	/* Kill machine if structures are wrong */
> > @@ -78,4 +102,7 @@ void main(void)
> >  		probe_cards(0);
> >  		set_mode(wakeup_header.video_mode);
> >  	}
> > +
> > +	if (wakeup_header.realmode_flags & 8)
> > +		flash_keyboard_leds();
> I do wish this little bit used an enum or definition instead of the hard
> coded 8 but since rest of the code does the same just consider it as
> me whining about style

I agree. It's lame that the original code is full of this hard coded
values rather than
some kind of enum or #define as it makes subsequent patches (such as
mine) inherit this same lameness.   I suspect we need to fix the
original code first rather than enforce it on this patch.


> 
> >  }
> > diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c
> > index ff93bc1..182617c 100644
> > --- a/arch/x86/kernel/acpi/sleep.c
> > +++ b/arch/x86/kernel/acpi/sleep.c
> > @@ -109,6 +109,8 @@ static int __init acpi_sleep_setup(char *str)
> >  			acpi_realmode_flags |= 2;
> >  		if (strncmp(str, "s3_beep", 7) == 0)
> >  			acpi_realmode_flags |= 4;
> > +		if (strncmp(str, "s3_leds", 7) == 0)
> > +			acpi_realmode_flags |= 8;
> >  #ifdef CONFIG_HIBERNATION
> >  		if (strncmp(str, "s4_nohwsig", 10) == 0)
> >  			acpi_no_s4_hw_signature();
> 
> This is really nice to have Colin, thanks
> 
> Acked-by: John Johansen <john.johansen at canonical.com>