Patchwork [PATCHv9,00/10] I2C fixes

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Submitter Datta, Shubhrajyoti
Date May 2, 2012, 2:32 p.m.
Message ID <1335969135-20858-1-git-send-email-shubhrajyoti@ti.com>
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Permalink /patch/156474/
State New
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Pull-request

git://gitorious.org/linus-tree/linus-tree.git i2c_omap-fixes

Comments

Datta, Shubhrajyoti - May 2, 2012, 2:32 p.m.
The patch series does the following

- Warn fixes if CONFIG_PM_RUNTIME is not selected.
- In case of i2c remove register access was done without any
 get_sync fix the same.
- Folds a patch from Tasslehoff to prevent any merge conflicts.
- Prevents the XDUF flag to be set if the underflow condition is not met.
- As per discussion in [1] .Adds a patch to rename the 1p153 errata and
 use the unique id instead as the section number in the recent errata
 docs has changed.

v9:
Fix the comments from Wolfram Sang

[1] http://www.spinics.net/lists/linux-i2c/msg07607.html

Tested on omap4sdp and omap3sdp.

The following changes since commit b821861b905a79f71746945237968c3382d99adc:

  Merge tag 'ktest-for-v3.4-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-ktest (2012-05-01 19:43:34 -0700)

are available in the git repository at:

  git://gitorious.org/linus-tree/linus-tree.git i2c_omap-fixes

Shubhrajyoti D (9):
      I2C: OMAP: make omap_i2c_unidle/idle functions depend on CONFIG_PM_RUNTIME
      I2C: OMAP: Fix the mismatch of pm_runtime enable and disable
      I2C: OMAP: Fix the interrupt clearing in OMAP4
      I2C: OMAP: Prevent the register access after pm_runtime_put in probe
      I2C: OMAP: Don't check if wait_for_completion_timeout() returns less than zero
      I2C: OMAP: Fix the crash in i2c remove
      I2C: OMAP: Handle error check for pm runtime
      I2C: OMAP: Do not set the XUDF(Transmit underflow) if the underflow is not reached
      I2C: OMAP: Rename the 1p153 to the erratum id i462

Tasslehoff Kjappfot (1):
      I2C: OMAP: prevent the overwrite of the errata flags

 drivers/i2c/busses/i2c-omap.c |  127 ++++++++++++++++++++---------------------
 1 files changed, 62 insertions(+), 65 deletions(-)
Wolfram Sang - May 12, 2012, 6:10 p.m.
On Wed, May 02, 2012 at 08:02:11PM +0530, Shubhrajyoti D wrote:
>     In omap_i2c_remove we are accessing the I2C_CON register without
>     enabling the clocks. Fix the same by enabling the clocks and disabling
>     it.
>     This fixes the following crash.
>     [  154.723022] ------------[ cut here ]------------
>     [  154.725677] WARNING: at arch/arm/mach-omap2/omap_l3_noc.c:112 l3_interrupt_handler+0x1b4/0x1c4()
>     [  154.725677] L3 custom error: MASTER:MPU TARGET:L4 PER2
>     [  154.742614] Modules linked in: i2c_omap(-)
>     [  154.746948] Backtrace:
>     [  154.746948] [<c0013078>] (dump_backtrace+0x0/0x110) from [<c026c158>] (dump_stack+0x18/0x1c)
>     [  154.752716]  r6:00000070 r5:c002c43c r4:df9b9e98 r3:df9b8000
>     [  154.764465] [<c026c140>] (dump_stack+0x0/0x1c) from [<c0041a2c>] (warn_slowpath_common+0x5c/0x6c)
>     [  154.768341] [<c00419d0>] (warn_slowpath_common+0x0/0x6c) from [<c0041ae0>] (warn_slowpath_fmt+0x38/0x40)
>     [  154.776153]  r8:00000180 r7:c0361594 r6:c0379b48 r5:00080003 r4:e0838b00
>     [  154.790771] r3:00000009
>     [  154.791778] [<c0041aa8>] (warn_slowpath_fmt+0x0/0x40) from [<c002c43c>] (l3_interrupt_handler+0x1b4/0x1c4)
>     [  154.803710]  r3:c0361598 r2:c02ef74c
>     [  154.807403] [<c002c288>] (l3_interrupt_handler+0x0/0x1c4) from [<c0085f44>] (handle_irq_event_percpu+0x58/0
>     [  154.818237]  r8:0000002a r7:00000000 r6:00000000 r5:df808054 r4:df8893c0
>     [  154.825378] [<c0085eec>] (handle_irq_event_percpu+0x0/0x188) from [<c00860b8>] (handle_irq_event+0x44/0x64)
>     [  154.835662] [<c0086074>] (handle_irq_event+0x0/0x64) from [<c0088ec0>] (handle_fasteoi_irq+0xa4/0x10c)
>     [  154.845458]  r6:0000002a r5:df808054 r4:df808000 r3:c034a150
>     [  154.846466] [<c0088e1c>] (handle_fasteoi_irq+0x0/0x10c) from [<c0085ed0>] (generic_handle_irq+0x30/0x38)
>     [  154.854278]  r5:c034aa48 r4:0000002a
>     [  154.862091] [<c0085ea0>] (generic_handle_irq+0x0/0x38) from [<c000fd38>] (handle_IRQ+0x60/0xc0)
>     [  154.874450]  r4:c034ea70 r3:000001f8
>     [  154.878234] [<c000fcd8>] (handle_IRQ+0x0/0xc0) from [<c0008478>] (gic_handle_irq+0x20/0x5c)
>     [  154.887023]  r7:ffffff40 r6:df9b9fb0 r5:c034e2b4 r4:0000001a
>     [  154.887054] [<c0008458>] (gic_handle_irq+0x0/0x5c) from [<c000ea80>] (__irq_usr+0x40/0x60)
>     [  154.901153] Exception stack(0xdf9b9fb0 to 0xdf9b9ff8)
>     [  154.907104] 9fa0:                                     beaf1f04 4006be00 0000000f 0000000c
>     [  154.915710] 9fc0: 4006c000 00000000 00008034 ffffff40 00000007 00000000 00000000 0007b8d7
>     [  154.916778] 9fe0: 00000000 beaf1b68 0000d23c 4005baf0 80000010 ffffffff
>     [  154.931335]  r6:ffffffff r5:80000010 r4:4005baf0 r3:beaf1f04
>     [  154.937316] ---[ end trace 1b75b31a2719ed21 ]--
> 
> Cc: Kevin Hilman <khilman@ti.com>
> Cc: Rajendra Nayak <rnayak@ti.com>
> Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>

I'd really like a comment from the PM experts if each and every driver
has to ensure that the clocks are enabled on remove like this?

> ---
>  drivers/i2c/busses/i2c-omap.c |    2 ++
>  1 files changed, 2 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
> index fec8d5c..44e8cfa 100644
> --- a/drivers/i2c/busses/i2c-omap.c
> +++ b/drivers/i2c/busses/i2c-omap.c
> @@ -1108,7 +1108,9 @@ omap_i2c_remove(struct platform_device *pdev)
>  
>  	free_irq(dev->irq, dev);
>  	i2c_del_adapter(&dev->adapter);
> +	pm_runtime_get_sync(&pdev->dev);
>  	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
> +	pm_runtime_put(&pdev->dev);
>  	pm_runtime_disable(&pdev->dev);
>  	iounmap(dev->base);
>  	kfree(dev);
> -- 
> 1.7.5.4
>
Wolfram Sang - May 12, 2012, 6:10 p.m.
On Wed, May 02, 2012 at 08:02:05PM +0530, Shubhrajyoti D wrote:
> 
> The patch series does the following
> 
> - Warn fixes if CONFIG_PM_RUNTIME is not selected.
> - In case of i2c remove register access was done without any
>  get_sync fix the same.
> - Folds a patch from Tasslehoff to prevent any merge conflicts.
> - Prevents the XDUF flag to be set if the underflow condition is not met.
> - As per discussion in [1] .Adds a patch to rename the 1p153 errata and
>  use the unique id instead as the section number in the recent errata
>  docs has changed.
> 
> v9:
> Fix the comments from Wolfram Sang

Patch 2 has my comment not addressed, so I stopped reviewing. It is
probably more helpful (and easier for me, too) if you do a changelog per
patch (and not of the whole series), then you can immediately see if
that specific changelog matches the current patch. 'git send-email
--annotate' might be helpful here.

Thanks,

   Wolfram
Datta, Shubhrajyoti - May 14, 2012, 11:26 a.m.
On Saturday 12 May 2012 11:40 PM, Wolfram Sang wrote:
>> Cc: Kevin Hilman <khilman@ti.com>
>> > Cc: Rajendra Nayak <rnayak@ti.com>
>> > Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
> I'd really like a comment from the PM experts if each and every driver
> has to ensure that the clocks are enabled on remove like this?
Just resent cc ing linux-pm

BTW also found that

Some others are also doing the same. eg:
 
drivers/mmc/host/omap_hsmmc.c
static int __devexit omap_hsmmc_remove(struct platform_device *pdev)
{
        struct omap_hsmmc_host *host = platform_get_drvdata(pdev);
        struct resource *res;

        pm_runtime_get_sync(host->dev);
        mmc_remove_host(host->mmc);

2. drivers/usb/musb/musb_core.c

static void musb_shutdown(struct platform_device *pdev)
{
        struct musb     *musb = dev_to_musb(&pdev->dev);
        unsigned long   flags;

        pm_runtime_get_sync(musb->controller);

Anyways will wait for feedback.




>
>> > ---
>> >  drivers/i2c/busses/i2c-omap.c |
Kevin Hilman - May 25, 2012, 9:51 p.m.
Hi Wolfram,

Wolfram Sang <w.sang@pengutronix.de> writes:

> On Wed, May 02, 2012 at 08:02:11PM +0530, Shubhrajyoti D wrote:
>>     In omap_i2c_remove we are accessing the I2C_CON register without
>>     enabling the clocks. Fix the same by enabling the clocks and disabling
>>     it.

[...]

> I'd really like a comment from the PM experts if each and every driver
> has to ensure that the clocks are enabled on remove like this?

Yes, this is correct.

In fact, this is the goal of runtime PM.  The driver itself tells the PM
core (using runtime PM) when the device needs to be accessible and when
it doesn't.

Technically speaking, the it's up to the platform-specific runtime PM
implementation to decide whether or not the clocks are actually disable
or not  (e.g. due to wakeup latency requirements, it might decide not to
cut clocks.)

Because of that, the changelog should be reworded to say something like
"ensure device is accessible" instead of "enable the clocks", because
the runtime PM implementation does more than just manage clocks.

Kevin

P.S. It's great to see you helping out maintaining i2c drivers.  Thanks!

P.P.S. Before you merge this, I would strongly recommend we wait for a
       few more Tested-bys, and a bit more description about how this
       was tested.  We've been having quite a few problems with
       regressions introduced in OMAP drivers that have not been well
       reviewed or tested.
Kevin Hilman - May 25, 2012, 9:57 p.m.
Shubhrajyoti D <shubhrajyoti@ti.com> writes:

> Currently the i2c driver calls the pm_runtime_enable and never
> the disable. This may cause a warning when pm_runtime_enable
> checks for the count match.Attempting to fix the same by calling
> pm_runtime_disable in the error and the remove path.

Looks right.

Can you be more specific in the changelog about when the errors/warning
happens?  e.g. why pm_runtime_enable() is called again?  Is this on
module unload/reload?

Other than that

Acked-by: Kevin Hilman <khilman@ti.com>


> Cc: Kevin Hilman <khilman@ti.com>
> Cc: Rajendra Nayak <rnayak@ti.com>
> Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
> ---
>  drivers/i2c/busses/i2c-omap.c |    2 ++
>  1 files changed, 2 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
> index 4f4188d..c851672 100644
> --- a/drivers/i2c/busses/i2c-omap.c
> +++ b/drivers/i2c/busses/i2c-omap.c
> @@ -1090,6 +1090,7 @@ err_unuse_clocks:
>  	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
>  	pm_runtime_put(dev->dev);
>  	iounmap(dev->base);
> +	pm_runtime_disable(&pdev->dev);
>  err_free_mem:
>  	platform_set_drvdata(pdev, NULL);
>  	kfree(dev);
> @@ -1110,6 +1111,7 @@ omap_i2c_remove(struct platform_device *pdev)
>  	free_irq(dev->irq, dev);
>  	i2c_del_adapter(&dev->adapter);
>  	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
> +	pm_runtime_disable(&pdev->dev);
>  	iounmap(dev->base);
>  	kfree(dev);
>  	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
Kevin Hilman - May 25, 2012, 10:06 p.m.
Shubhrajyoti D <shubhrajyoti@ti.com> writes:

> If PM runtime get_sync fails return with the error
> so that no further reads/writes goes through the interface.
> This will avoid possible abort. Add a error message in case
> of failure with the cause of the failure.
>
> Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
> ---
>  drivers/i2c/busses/i2c-omap.c |   14 +++++++++++---
>  1 files changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
> index 44e8cfa..a72874e 100644
> --- a/drivers/i2c/busses/i2c-omap.c
> +++ b/drivers/i2c/busses/i2c-omap.c
> @@ -585,7 +585,9 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
>  	int i;
>  	int r;
>  
> -	pm_runtime_get_sync(dev->dev);
> +	r = pm_runtime_get_sync(dev->dev);
> +	if (r < 0)
> +		return r;

nit: please use IS_ERR_VALUE() 

Kevin
Kevin Hilman - May 25, 2012, 10:09 p.m.
Shubhrajyoti D <shubhrajyoti@ti.com> writes:

> Currently in the 1.153 errata handling while waiting for transmitter
> underflow if NACK is got the XUDF(Transmit underflow) flag is also set.

-EOVERFLOW

This sentence needs a rewrite and some punctuation.  It does not read well.

> The flag is set after wait for the condition is over.
>
> Cc: Alexander Shishkin <virtuoso@slind.org>
> Acked-by: Moiz Sonasath <m-sonasath@ti.com>
> Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
> ---
>  drivers/i2c/busses/i2c-omap.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
> index 43b0efb..c0aa16b 100644
> --- a/drivers/i2c/busses/i2c-omap.c
> +++ b/drivers/i2c/busses/i2c-omap.c
> @@ -730,7 +730,6 @@ static int errata_omap3_1p153(struct omap_i2c_dev *dev, u16 *stat, int *err)
>  		if (*stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) {
>  			omap_i2c_ack_stat(dev, *stat & (OMAP_I2C_STAT_XRDY |
>  							OMAP_I2C_STAT_XDR));
> -			*err |= OMAP_I2C_STAT_XUDF;
>  			return -ETIMEDOUT;
>  		}
>  
> @@ -743,6 +742,7 @@ static int errata_omap3_1p153(struct omap_i2c_dev *dev, u16 *stat, int *err)
>  		return 0;
>  	}
>  
> +	*err |= OMAP_I2C_STAT_XUDF;
>  	return 0;
>  }

Kevin
Kevin Hilman - May 25, 2012, 10:13 p.m.
Shubhrajyoti D <shubhrajyoti@ti.com> writes:

> The patch series does the following
>
> - Warn fixes if CONFIG_PM_RUNTIME is not selected.
> - In case of i2c remove register access was done without any
>  get_sync fix the same.
> - Folds a patch from Tasslehoff to prevent any merge conflicts.
> - Prevents the XDUF flag to be set if the underflow condition is not met.
> - As per discussion in [1] .Adds a patch to rename the 1p153 errata and
>  use the unique id instead as the section number in the recent errata
>  docs has changed.
>
> v9:
> Fix the comments from Wolfram Sang
>
> [1] http://www.spinics.net/lists/linux-i2c/msg07607.html
>
> Tested on omap4sdp and omap3sdp.

Can you also describe how it was tested?  

With the runtime PM changes, does it still hit full-chip retention in
idle and suspend after these changes?

I had a few minor comments on this version, otherwise feel free add

Reviewed-by: Kevin Hilman <khilman@ti.com>

That being said, before this is merged, I woudl like to see some more
non-author Tested-bys.  We've been having lots of regressions of late
from OMAP drivers that are not being sufficiently tested before
merging.  We need to ensure proper testing before merge.

Other testers should also report what platforms they tested on, and how
it was tested.

Thanks,

Kevin
Datta, Shubhrajyoti - May 28, 2012, 9:52 a.m.
Hi Kevin,


On Saturday 26 May 2012 03:43 AM, Kevin Hilman wrote:
> Shubhrajyoti D <shubhrajyoti@ti.com> writes:
>
>> The patch series does the following
>>
>> - Warn fixes if CONFIG_PM_RUNTIME is not selected.
>> - In case of i2c remove register access was done without any
>>  get_sync fix the same.
>> - Folds a patch from Tasslehoff to prevent any merge conflicts.
>> - Prevents the XDUF flag to be set if the underflow condition is not met.
>> - As per discussion in [1] .Adds a patch to rename the 1p153 errata and
>>  use the unique id instead as the section number in the recent errata
>>  docs has changed.
>>
>> v9:
>> Fix the comments from Wolfram Sang
>>
>> [1] http://www.spinics.net/lists/linux-i2c/msg07607.html
>>
>> Tested on omap4sdp and omap3sdp.
> Can you also describe how it was tested?  
I did basic functionality  tests using i2c-tools.
>
> With the runtime PM changes, does it still hit full-chip retention in
> idle and suspend after these changes?
Will check.
>
> I had a few minor comments on this version,
Will fixup and resend.
>  otherwise feel free add
>
> Reviewed-by: Kevin Hilman <khilman@ti.com>
Thanks for your review.
>
> That being said, before this is merged, I woudl like to see some more
> non-author Tested-bys.  We've been having lots of regressions of late
> from OMAP drivers that are not being sufficiently tested before
> merging.  We need to ensure proper testing before merge.
>
> Other testers should also report what platforms they tested on, and how
> it was tested.
>
> Thanks,
>
> Kevin
Datta, Shubhrajyoti - May 28, 2012, 9:54 a.m.
On Saturday 26 May 2012 05:10 AM, Kevin Hilman wrote:
> Shubhrajyoti,
>
> Can you add one more patch to this series.
Yes will add it.

Thanks,
Shubhro
>
> The patch below from Neil Brown has been circulating for awhile, and
> I've been using it locally for awhile now too.  It would help if it got
> into this series and got some broader testing.
>
> Thanks,
>
> Kevin
Datta, Shubhrajyoti - May 28, 2012, 9:59 a.m.
On Saturday 26 May 2012 03:27 AM, Kevin Hilman wrote:
> Looks right.
>
> Can you be more specific in the changelog about when the errors/warning
> happens?
By the way the count cribs Unbalanced pm_runtime_enable!
is what happens.

I found it by review, I did the testing with this patch.

Since there was an access without get_sync I was seeing
some other issues.

Did not test with the fix and without this patch.
>   e.g. why pm_runtime_enable() is called again?  Is this on
> module unload/reload?
>
> Other than that
>
> Acked-by: Kevin Hilman <khilman@ti.com>
Thanks.
Datta, Shubhrajyoti - May 28, 2012, 11:22 a.m.
On Saturday 26 May 2012 03:36 AM, Kevin Hilman wrote:
>> +	r = pm_runtime_get_sync(dev->dev);
>> > +	if (r < 0)
>> > +		return r;
> nit: please use IS_ERR_VALUE() 
Will fix that and resend.
> Kevin