LCDC problem after commit 794d78fea51504bad3880d14f354a9847f318f25

LCDC problem after commit 794d78fea51504bad3880d14f354a9847f318f25

[Rafael J. Wysocki]

Hi,

Unfortunately, after commit 794d78fea51504bad3880d14f354a9847f318f25
(drivers: sh: late disabling of clocks V2) the LCDC screen on my
Mackerel board goes off (late) during boot and cannot be turned on
by any way AFAICS (the backlight remains on, though).

It looks like the late disabling of clocks interacts badly with the
clock management done by PM domains.

Thanks,
Rafael

Re: LCDC problem after commit 794d78fea51504bad3880d14f354a9847f318f25

[Magnus Damm]

Hi Rafael,

On Mon, Aug 8, 2011 at 8:25 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> Hi,
>
> Unfortunately, after commit 794d78fea51504bad3880d14f354a9847f318f25
> (drivers: sh: late disabling of clocks V2) the LCDC screen on my
> Mackerel board goes off (late) during boot and cannot be turned on
> by any way AFAICS (the backlight remains on, though).
>
> It looks like the late disabling of clocks interacts badly with the
> clock management done by PM domains.

This is most likely showing a so-far-not-handled clock dependency for
the LCDC hardware. I'll have a look.

Thanks,

/ magnus

Re: LCDC problem after commit 794d78fea51504bad3880d14f354a9847f318f25

[Magnus Damm]

Hi Rafael,

On Mon, Aug 8, 2011 at 8:25 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> Hi,
>
> Unfortunately, after commit 794d78fea51504bad3880d14f354a9847f318f25
> (drivers: sh: late disabling of clocks V2) the LCDC screen on my
> Mackerel board goes off (late) during boot and cannot be turned on
> by any way AFAICS (the backlight remains on, though).
>
> It looks like the late disabling of clocks interacts badly with the
> clock management done by PM domains.

This is most likely showing a so-far-not-handled clock dependency for
the LCDC hardware. I'll have a look.

Thanks,

/ magnus

Re: LCDC problem after commit 794d78fea51504bad3880d14f354a9847f318f25

[Magnus Damm]

Hi Rafael,

[Dropped Linux-PM list, added Laurent and Damian]

On Mon, Aug 8, 2011 at 10:46 AM, Magnus Damm <magnus.damm@gmail.com> wrote:
> On Mon, Aug 8, 2011 at 8:25 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
>> Unfortunately, after commit 794d78fea51504bad3880d14f354a9847f318f25
>> (drivers: sh: late disabling of clocks V2) the LCDC screen on my
>> Mackerel board goes off (late) during boot and cannot be turned on
>> by any way AFAICS (the backlight remains on, though).
>>
>> It looks like the late disabling of clocks interacts badly with the
>> clock management done by PM domains.
>
> This is most likely showing a so-far-not-handled clock dependency for
> the LCDC hardware. I'll have a look.

Further investigation shows that this only triggers when the MERAM is
enabled in the kernel configuration using CONFIG_FB_SH_MOBILE_MERAM=y.
So this seems more related to MERAM power management than LCDC.

Digging a bit deeper makes it clear that the sh_mobile_meram.c driver
in upstream doesn't seem to include any Runtime PM code. I recall
seeing various versions posted to the mailing list.

Laurent [CC], can you please provide us with a list of outstanding
LCDC/MERAM patches to make this work as expected? I realize there are
quite a few outstanding LCDC patches, but if possible please provide a
list of the bare minimum to make this work with 3.1-rc.

I suspect that Damian [CC] is busy, but if time allows perhaps he can
share his ideas as well.

When looking into this I noticed that the MERAM parent clock
assignment seems broken:

static struct clk mstp_clks[MSTP_NR] = {
	...
	[MSTP113] = MSTP(&div6_clks[DIV6_SUB], SMSTPCR1, 13, 0), /* MERAM */

Judging by the "Clock Assignment to Modules" table in the CPGA chapter
of the sh7372 data sheet, this should probably be &div4_clks[DIV4_S]
or &div4_clks[DIV4_B]. But before dealing with the parent accounting
we need to have Runtime PM support included in the MERAM driver.

Cheers,

/ magnus

Re: LCDC problem after commit 794d78fea51504bad3880d14f354a9847f318f25

[Damian Hobson-Garcia]

Hi Magnus,
> Hi Rafael,
> 
> [Dropped Linux-PM list, added Laurent and Damian]
> 
> Laurent [CC], can you please provide us with a list of outstanding
> LCDC/MERAM patches to make this work as expected? I realize there are
> quite a few outstanding LCDC patches, but if possible please provide a
> list of the bare minimum to make this work with 3.1-rc.
> 
> I suspect that Damian [CC] is busy, but if time allows perhaps he can
> share his ideas as well.
I don't really know about the LCDC patches, but for the MERAM side the
top 5 commits from the common/fbdev-meram branch (fbdev:
sh_mobile_meram: Enable runtime PM .. fbdev: sh_mobile_lcdc: Turn dot
clock on...) + Laurent's latest patch series (sh_mobile_meram cleanup
and fixes), which fixes a suspend bug, should be everything.

If you only want the runtime portion then you can probably get by with
just the common/fbdev-meram branch.

Thanks,
Damian

Re: LCDC problem after commit 794d78fea51504bad3880d14f354a9847f318f25

[Laurent Pinchart]

Hi Magnus,

Sorry for the late reply.

On Tuesday 09 August 2011 12:48:44 Magnus Damm wrote:
> On Mon, Aug 8, 2011 at 10:46 AM, Magnus Damm <magnus.damm@gmail.com> wrote:
> > On Mon, Aug 8, 2011 at 8:25 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> >> Unfortunately, after commit 794d78fea51504bad3880d14f354a9847f318f25
> >> (drivers: sh: late disabling of clocks V2) the LCDC screen on my
> >> Mackerel board goes off (late) during boot and cannot be turned on
> >> by any way AFAICS (the backlight remains on, though).
> >> 
> >> It looks like the late disabling of clocks interacts badly with the
> >> clock management done by PM domains.
> > 
> > This is most likely showing a so-far-not-handled clock dependency for
> > the LCDC hardware. I'll have a look.
> 
> Further investigation shows that this only triggers when the MERAM is
> enabled in the kernel configuration using CONFIG_FB_SH_MOBILE_MERAM=y.
> So this seems more related to MERAM power management than LCDC.
> 
> Digging a bit deeper makes it clear that the sh_mobile_meram.c driver
> in upstream doesn't seem to include any Runtime PM code. I recall
> seeing various versions posted to the mailing list.
> 
> Laurent [CC], can you please provide us with a list of outstanding
> LCDC/MERAM patches to make this work as expected? I realize there are
> quite a few outstanding LCDC patches, but if possible please provide a
> list of the bare minimum to make this work with 3.1-rc.

I've pushed my pending patches to http://git.linuxtv.org/pinchartl/fbdev.git 
in the pm-domains branch. The first 19 patches have been picked from mailing 
lists. Hopefully they're the latest versions that have been posted. The next 
11 patches shouldn't be required to enable runtime PM with the MERAM, but they 
provide code cleanup and bug fixes.

Are Rafael' and Damian's patches ready for mainline ? If so, when will they be 
pulled ? They're more than one month old, I was expecting them to hit v3.1-
rc1. The backlog is growing, which makes collaboration more difficult.

> I suspect that Damian [CC] is busy, but if time allows perhaps he can
> share his ideas as well.
> 
> When looking into this I noticed that the MERAM parent clock
> assignment seems broken:
> 
> static struct clk mstp_clks[MSTP_NR] = {
> 	...
> 	[MSTP113] = MSTP(&div6_clks[DIV6_SUB], SMSTPCR1, 13, 0), /* MERAM */
> 
> Judging by the "Clock Assignment to Modules" table in the CPGA chapter
> of the sh7372 data sheet, this should probably be &div4_clks[DIV4_S]
> or &div4_clks[DIV4_B]. But before dealing with the parent accounting
> we need to have Runtime PM support included in the MERAM driver.

-- 
Regards,

Laurent Pinchart

Re: LCDC problem after commit 794d78fea51504bad3880d14f354a9847f318f25

[Rafael J. Wysocki]

On Thursday, August 11, 2011, Laurent Pinchart wrote:
> Hi Magnus,
> 
> Sorry for the late reply.
> 
> On Tuesday 09 August 2011 12:48:44 Magnus Damm wrote:
> > On Mon, Aug 8, 2011 at 10:46 AM, Magnus Damm <magnus.damm@gmail.com> wrote:
> > > On Mon, Aug 8, 2011 at 8:25 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > >> Unfortunately, after commit 794d78fea51504bad3880d14f354a9847f318f25
> > >> (drivers: sh: late disabling of clocks V2) the LCDC screen on my
> > >> Mackerel board goes off (late) during boot and cannot be turned on
> > >> by any way AFAICS (the backlight remains on, though).
> > >> 
> > >> It looks like the late disabling of clocks interacts badly with the
> > >> clock management done by PM domains.
> > > 
> > > This is most likely showing a so-far-not-handled clock dependency for
> > > the LCDC hardware. I'll have a look.
> > 
> > Further investigation shows that this only triggers when the MERAM is
> > enabled in the kernel configuration using CONFIG_FB_SH_MOBILE_MERAM=y.
> > So this seems more related to MERAM power management than LCDC.
> > 
> > Digging a bit deeper makes it clear that the sh_mobile_meram.c driver
> > in upstream doesn't seem to include any Runtime PM code. I recall
> > seeing various versions posted to the mailing list.
> > 
> > Laurent [CC], can you please provide us with a list of outstanding
> > LCDC/MERAM patches to make this work as expected? I realize there are
> > quite a few outstanding LCDC patches, but if possible please provide a
> > list of the bare minimum to make this work with 3.1-rc.
> 
> I've pushed my pending patches to http://git.linuxtv.org/pinchartl/fbdev.git 
> in the pm-domains branch. The first 19 patches have been picked from mailing 
> lists. Hopefully they're the latest versions that have been posted. The next 
> 11 patches shouldn't be required to enable runtime PM with the MERAM, but they 
> provide code cleanup and bug fixes.
> 
> Are Rafael' and Damian's patches ready for mainline ? If so, when will they be 
> pulled ? They're more than one month old, I was expecting them to hit v3.1-
> rc1. The backlog is growing, which makes collaboration more difficult.

Which of my patches are you referring to in particular?

Rafael

Re: LCDC problem after commit 794d78fea51504bad3880d14f354a9847f318f25

[Laurent Pinchart]

Hi Rafael,

On Thursday 11 August 2011 21:37:04 Rafael J. Wysocki wrote:
> On Thursday, August 11, 2011, Laurent Pinchart wrote:
> > On Tuesday 09 August 2011 12:48:44 Magnus Damm wrote:
> > > On Mon, Aug 8, 2011 at 10:46 AM, Magnus Damm wrote:
> > > > On Mon, Aug 8, 2011 at 8:25 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > > >> Unfortunately, after commit 794d78fea51504bad3880d14f354a9847f318f25
> > > >> (drivers: sh: late disabling of clocks V2) the LCDC screen on my
> > > >> Mackerel board goes off (late) during boot and cannot be turned on
> > > >> by any way AFAICS (the backlight remains on, though).
> > > >> 
> > > >> It looks like the late disabling of clocks interacts badly with the
> > > >> clock management done by PM domains.
> > > > 
> > > > This is most likely showing a so-far-not-handled clock dependency for
> > > > the LCDC hardware. I'll have a look.
> > > 
> > > Further investigation shows that this only triggers when the MERAM is
> > > enabled in the kernel configuration using CONFIG_FB_SH_MOBILE_MERAM=y.
> > > So this seems more related to MERAM power management than LCDC.
> > > 
> > > Digging a bit deeper makes it clear that the sh_mobile_meram.c driver
> > > in upstream doesn't seem to include any Runtime PM code. I recall
> > > seeing various versions posted to the mailing list.
> > > 
> > > Laurent [CC], can you please provide us with a list of outstanding
> > > LCDC/MERAM patches to make this work as expected? I realize there are
> > > quite a few outstanding LCDC patches, but if possible please provide a
> > > list of the bare minimum to make this work with 3.1-rc.
> > 
> > I've pushed my pending patches to
> > http://git.linuxtv.org/pinchartl/fbdev.git in the pm-domains branch. The
> > first 19 patches have been picked from mailing lists. Hopefully they're
> > the latest versions that have been posted. The next 11 patches shouldn't
> > be required to enable runtime PM with the MERAM, but they provide code
> > cleanup and bug fixes.
> > 
> > Are Rafael' and Damian's patches ready for mainline ? If so, when will
> > they be pulled ? They're more than one month old, I was expecting them
> > to hit v3.1- rc1. The backlog is growing, which makes collaboration more
> > difficult.
> 
> Which of my patches are you referring to in particular?

My bad, your patches are in v3.1-rc1. I had rebased my branch on top of the 
wrong tag. We still need to push Damian's MERAM runtime PM patches, as well as 
mine.

-- 
Regards,

Laurent Pinchart

Re: LCDC problem after commit 794d78fea51504bad3880d14f354a9847f318f25

[Laurent Pinchart]

Hi Damian,

On Friday 12 August 2011 11:59:10 Laurent Pinchart wrote:
> On Thursday 11 August 2011 21:37:04 Rafael J. Wysocki wrote:
> > On Thursday, August 11, 2011, Laurent Pinchart wrote:
> > > On Tuesday 09 August 2011 12:48:44 Magnus Damm wrote:
> > > > On Mon, Aug 8, 2011 at 10:46 AM, Magnus Damm wrote:
> > > > > On Mon, Aug 8, 2011 at 8:25 AM, Rafael J. Wysocki wrote:
> > > > >> Unfortunately, after commit
> > > > >> 794d78fea51504bad3880d14f354a9847f318f25 (drivers: sh: late
> > > > >> disabling of clocks V2) the LCDC screen on my Mackerel board goes
> > > > >> off (late) during boot and cannot be turned on by any way AFAICS
> > > > >> (the backlight remains on, though).
> > > > >> 
> > > > >> It looks like the late disabling of clocks interacts badly with
> > > > >> the clock management done by PM domains.
> > > > > 
> > > > > This is most likely showing a so-far-not-handled clock dependency
> > > > > for the LCDC hardware. I'll have a look.
> > > > 
> > > > Further investigation shows that this only triggers when the MERAM is
> > > > enabled in the kernel configuration using
> > > > CONFIG_FB_SH_MOBILE_MERAM=y. So this seems more related to MERAM
> > > > power management than LCDC.
> > > > 
> > > > Digging a bit deeper makes it clear that the sh_mobile_meram.c driver
> > > > in upstream doesn't seem to include any Runtime PM code. I recall
> > > > seeing various versions posted to the mailing list.
> > > > 
> > > > Laurent [CC], can you please provide us with a list of outstanding
> > > > LCDC/MERAM patches to make this work as expected? I realize there are
> > > > quite a few outstanding LCDC patches, but if possible please provide
> > > > a list of the bare minimum to make this work with 3.1-rc.
> > > 
> > > I've pushed my pending patches to
> > > http://git.linuxtv.org/pinchartl/fbdev.git in the pm-domains branch.
> > > The first 19 patches have been picked from mailing lists. Hopefully
> > > they're the latest versions that have been posted. The next 11 patches
> > > shouldn't be required to enable runtime PM with the MERAM, but they
> > > provide code cleanup and bug fixes.
> > > 
> > > Are Rafael' and Damian's patches ready for mainline ? If so, when will
> > > they be pulled ? They're more than one month old, I was expecting them
> > > to hit v3.1- rc1. The backlog is growing, which makes collaboration
> > > more difficult.
> > 
> > Which of my patches are you referring to in particular?
> 
> My bad, your patches are in v3.1-rc1. I had rebased my branch on top of the
> wrong tag. We still need to push Damian's MERAM runtime PM patches, as well
> as mine.

Do you plan to push your MERAM runtime PM patches (available at 
http://git.linuxtv.org/pinchartl/fbdev.git/shortlog/refs/heads/pm-domains 
rebased on top of v3.1-rc2) ?

-- 
Regards,

Laurent Pinchart

Re: LCDC problem after commit 794d78fea51504bad3880d14f354a9847f318f25

[Damian Hobson-Garcia]

Hi Laurent,

On 2011/08/19 15:24, Laurent Pinchart wrote:
> Hi Damian,
> 
> On Friday 12 August 2011 11:59:10 Laurent Pinchart wrote:
>> On Thursday 11 August 2011 21:37:04 Rafael J. Wysocki wrote:
>>> On Thursday, August 11, 2011, Laurent Pinchart wrote:
>>>> On Tuesday 09 August 2011 12:48:44 Magnus Damm wrote:
>>>>> On Mon, Aug 8, 2011 at 10:46 AM, Magnus Damm wrote:
>>>>>> On Mon, Aug 8, 2011 at 8:25 AM, Rafael J. Wysocki wrote:
>>>>>>> Unfortunately, after commit
>>>>>>> 794d78fea51504bad3880d14f354a9847f318f25 (drivers: sh: late
>>>>>>> disabling of clocks V2) the LCDC screen on my Mackerel board goes
>>>>>>> off (late) during boot and cannot be turned on by any way AFAICS
>>>>>>> (the backlight remains on, though).
>>>>>>>
>>>>>>> It looks like the late disabling of clocks interacts badly with
>>>>>>> the clock management done by PM domains.
>>>>>>
>>>>>> This is most likely showing a so-far-not-handled clock dependency
>>>>>> for the LCDC hardware. I'll have a look.
>>>>>
>>>>> Further investigation shows that this only triggers when the MERAM is
>>>>> enabled in the kernel configuration using
>>>>> CONFIG_FB_SH_MOBILE_MERAM=y. So this seems more related to MERAM
>>>>> power management than LCDC.
>>>>>
>>>>> Digging a bit deeper makes it clear that the sh_mobile_meram.c driver
>>>>> in upstream doesn't seem to include any Runtime PM code. I recall
>>>>> seeing various versions posted to the mailing list.
>>>>>
>>>>> Laurent [CC], can you please provide us with a list of outstanding
>>>>> LCDC/MERAM patches to make this work as expected? I realize there are
>>>>> quite a few outstanding LCDC patches, but if possible please provide
>>>>> a list of the bare minimum to make this work with 3.1-rc.
>>>>
>>>> I've pushed my pending patches to
>>>> http://git.linuxtv.org/pinchartl/fbdev.git in the pm-domains branch.
>>>> The first 19 patches have been picked from mailing lists. Hopefully
>>>> they're the latest versions that have been posted. The next 11 patches
>>>> shouldn't be required to enable runtime PM with the MERAM, but they
>>>> provide code cleanup and bug fixes.
>>>>
>>>> Are Rafael' and Damian's patches ready for mainline ? If so, when will
>>>> they be pulled ? They're more than one month old, I was expecting them
>>>> to hit v3.1- rc1. The backlog is growing, which makes collaboration
>>>> more difficult.
>>>
>>> Which of my patches are you referring to in particular?
>>
>> My bad, your patches are in v3.1-rc1. I had rebased my branch on top of the
>> wrong tag. We still need to push Damian's MERAM runtime PM patches, as well
>> as mine.
> 
> Do you plan to push your MERAM runtime PM patches (available at 
> http://git.linuxtv.org/pinchartl/fbdev.git/shortlog/refs/heads/pm-domains 
> rebased on top of v3.1-rc2) ?
> 

Sorry for my late reply.  Yes the plan was to push the MERAM runtime
patches. I see that you've already included them in a PULL request, cc:d
to the list, so that's fine by me.

Thanks,
Damian

LCDC problem after commit 794d78fea51504bad3880d14f354a9847f318f25

[Rafael J. Wysocki]

Hi,

Unfortunately, after commit 794d78fea51504bad3880d14f354a9847f318f25
(drivers: sh: late disabling of clocks V2) the LCDC screen on my
Mackerel board goes off (late) during boot and cannot be turned on
by any way AFAICS (the backlight remains on, though).

It looks like the late disabling of clocks interacts badly with the
clock management done by PM domains.

Thanks,
Rafael