[PATCH] EDAC, altera: wrap edac pm with a CONFIG_PM

[PATCH] EDAC, altera: wrap edac pm with a CONFIG_PM

[dinguyen]

From: Alan Tull <atull@opensource.altera.com>

Suspend-to-RAM and EDAC support are mutually exclusive on
SOCFPGA.  If the EDAC is enabled, it will prevent the
platform from going into suspend.

Signed-off-by: Alan Tull <atull@opensource.altera.com>
Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Acked-by: Borislav Petkov <bp@suse.de>
---
Hi Boris,

Please apply this patch to your for-next? This was part of Alan Tull's
suspend-to-ram patch that I was going to take through arm-soc. But if
I left the patch as it was, it would have caused a merge conflict for
v4.2.

Thanks,
Dinh
---
 drivers/edac/altera_edac.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/edac/altera_edac.c b/drivers/edac/altera_edac.c
index 182c741..23ef091 100644
--- a/drivers/edac/altera_edac.c
+++ b/drivers/edac/altera_edac.c
@@ -477,11 +477,31 @@ static int altr_sdram_remove(struct platform_device *pdev)
 	return 0;
 }
 
+/*
+ * If you want to suspend, need to disable EDAC by removing it
+ * from the device tree or defconfig.
+ */
+#ifdef CONFIG_PM
+static int altr_sdram_prepare(struct device *dev)
+{
+	pr_err("Suspend not allowed when EDAC is enabled.\n");
+
+	return -EPERM;
+}
+
+static const struct dev_pm_ops altr_sdram_pm_ops = {
+	.prepare = altr_sdram_prepare,
+};
+#endif
+
 static struct platform_driver altr_sdram_edac_driver = {
 	.probe = altr_sdram_probe,
 	.remove = altr_sdram_remove,
 	.driver = {
 		.name = "altr_sdram_edac",
+#ifdef CONFIG_PM
+		.pm = &altr_sdram_pm_ops,
+#endif
 		.of_match_table = altr_sdram_ctrl_of_match,
 	},
 };
-- 
2.2.1

Re: [PATCH] EDAC, altera: wrap edac pm with a CONFIG_PM

[Borislav Petkov]

On Fri, Jun 05, 2015 at 08:49:15AM -0500, dinguyen@opensource.altera.com wrote:
> From: Alan Tull <atull@opensource.altera.com>
> 
> Suspend-to-RAM and EDAC support are mutually exclusive on
> SOCFPGA.  If the EDAC is enabled, it will prevent the
> platform from going into suspend.

Btw, what is exactly the problem with EDAC being enabled and not being
able to suspend? Is it a hardware issue?

Because if it is sw one, we probably could change the EDAC core to
accomodate power management. On x86 we don't need to do anything special
to EDAC wrt PM though - we simply suspend.

Thanks.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
--

Re: [PATCH] EDAC, altera: wrap edac pm with a CONFIG_PM

[Thor Thayer]

Hi Boris,

On 06/05/2015 10:15 AM, Borislav Petkov wrote:
> On Fri, Jun 05, 2015 at 08:49:15AM -0500, dinguyen@opensource.altera.com wrote:
>> From: Alan Tull <atull@opensource.altera.com>
>>
>> Suspend-to-RAM and EDAC support are mutually exclusive on
>> SOCFPGA.  If the EDAC is enabled, it will prevent the
>> platform from going into suspend.
>
> Btw, what is exactly the problem with EDAC being enabled and not being
> able to suspend? Is it a hardware issue?
>
> Because if it is sw one, we probably could change the EDAC core to
> accomodate power management. On x86 we don't need to do anything special
> to EDAC wrt PM though - we simply suspend.
>
> Thanks.
>

Yes, in our case, it is a hardware issue but I'm still gathering 
information.

The IRQ vectors for OCRAM reside on DDR and in Suspend-to-RAM mode we're 
executing out of OCRAM. If an ECC error occurs, we can't handle it so it 
was decided to make them mutually exclusive.

Thor

Re: [PATCH] EDAC, altera: wrap edac pm with a CONFIG_PM

[Borislav Petkov]

On Fri, Jun 05, 2015 at 04:40:29PM -0500, Thor Thayer wrote:
> Yes, in our case, it is a hardware issue but I'm still gathering
> information.
> 
> The IRQ vectors for OCRAM reside on DDR and in Suspend-to-RAM mode we're
> executing out of OCRAM. If an ECC error occurs, we can't handle it so it was
> decided to make them mutually exclusive.

Thanks Thor,

that's actually a good-enough explanation for me - I was just making
sure that it is not some silly EDAC core limitation preventing you guys
from doing suspend.

Anyway, I've committed the version below, if you still feel you want to
improve the explanation, no problem - it is the topmost patch on the
branch and I can amend it easily.

---
From: Alan Tull <atull@opensource.altera.com>
Date: Fri, 5 Jun 2015 08:49:15 -0500
Subject: [PATCH] EDAC, altera: Do not allow suspend when EDAC is enabled

Suspend-to-RAM and EDAC support are mutually exclusive on SOCFPGA. If
EDAC is enabled, it will prevent the platform from going into suspend.

The reason is that the IRQ vectors for OCRAM reside on DDR and in
Suspend-to-RAM mode we're executing out of OCRAM. If an ECC error
occurs, we can't handle it so it was decided to make them mutually
exclusive.

Signed-off-by: Alan Tull <atull@opensource.altera.com>
Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Cc: dinh.linux@gmail.com
Cc: dougthompson@xmission.com
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: mchehab@osg.samsung.com
Cc: tthayer@opensource.altera.com
Link: http://lkml.kernel.org/r/1433512155-9906-1-git-send-email-dinguyen@opensource.altera.com
Signed-off-by: Borislav Petkov <bp@suse.de>
---
 drivers/edac/altera_edac.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/edac/altera_edac.c b/drivers/edac/altera_edac.c
index 182c741adf3e..23ef0917483c 100644
--- a/drivers/edac/altera_edac.c
+++ b/drivers/edac/altera_edac.c
@@ -477,11 +477,31 @@ static int altr_sdram_remove(struct platform_device *pdev)
 	return 0;
 }
 
+/*
+ * If you want to suspend, need to disable EDAC by removing it
+ * from the device tree or defconfig.
+ */
+#ifdef CONFIG_PM
+static int altr_sdram_prepare(struct device *dev)
+{
+	pr_err("Suspend not allowed when EDAC is enabled.\n");
+
+	return -EPERM;
+}
+
+static const struct dev_pm_ops altr_sdram_pm_ops = {
+	.prepare = altr_sdram_prepare,
+};
+#endif
+
 static struct platform_driver altr_sdram_edac_driver = {
 	.probe = altr_sdram_probe,
 	.remove = altr_sdram_remove,
 	.driver = {
 		.name = "altr_sdram_edac",
+#ifdef CONFIG_PM
+		.pm = &altr_sdram_pm_ops,
+#endif
 		.of_match_table = altr_sdram_ctrl_of_match,
 	},
 };
-- 
2.3.5

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
--

Re: [PATCH] EDAC, altera: wrap edac pm with a CONFIG_PM

[atull]

On Sat, 6 Jun 2015, Borislav Petkov wrote:

> On Fri, Jun 05, 2015 at 04:40:29PM -0500, Thor Thayer wrote:
> > Yes, in our case, it is a hardware issue but I'm still gathering
> > information.
> > 
> > The IRQ vectors for OCRAM reside on DDR and in Suspend-to-RAM mode we're
> > executing out of OCRAM. If an ECC error occurs, we can't handle it so it was
> > decided to make them mutually exclusive.
> 
> Thanks Thor,
> 
> that's actually a good-enough explanation for me - I was just making
> sure that it is not some silly EDAC core limitation preventing you guys
> from doing suspend.
> 
> Anyway, I've committed the version below, if you still feel you want to
> improve the explanation, no problem - it is the topmost patch on the
> branch and I can amend it easily.
> 

Thanks Boris.  That looks good.

Regards,
Alan


> ---
> From: Alan Tull <atull@opensource.altera.com>
> Date: Fri, 5 Jun 2015 08:49:15 -0500
> Subject: [PATCH] EDAC, altera: Do not allow suspend when EDAC is enabled
> 
> Suspend-to-RAM and EDAC support are mutually exclusive on SOCFPGA. If
> EDAC is enabled, it will prevent the platform from going into suspend.
> 
> The reason is that the IRQ vectors for OCRAM reside on DDR and in
> Suspend-to-RAM mode we're executing out of OCRAM. If an ECC error
> occurs, we can't handle it so it was decided to make them mutually
> exclusive.
> 
> Signed-off-by: Alan Tull <atull@opensource.altera.com>
> Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
> Cc: dinh.linux@gmail.com
> Cc: dougthompson@xmission.com
> Cc: linux-edac <linux-edac@vger.kernel.org>
> Cc: mchehab@osg.samsung.com
> Cc: tthayer@opensource.altera.com
> Link: http://lkml.kernel.org/r/1433512155-9906-1-git-send-email-dinguyen@opensource.altera.com
> Signed-off-by: Borislav Petkov <bp@suse.de>
> ---
>  drivers/edac/altera_edac.c | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> diff --git a/drivers/edac/altera_edac.c b/drivers/edac/altera_edac.c
> index 182c741adf3e..23ef0917483c 100644
> --- a/drivers/edac/altera_edac.c
> +++ b/drivers/edac/altera_edac.c
> @@ -477,11 +477,31 @@ static int altr_sdram_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> +/*
> + * If you want to suspend, need to disable EDAC by removing it
> + * from the device tree or defconfig.
> + */
> +#ifdef CONFIG_PM
> +static int altr_sdram_prepare(struct device *dev)
> +{
> +	pr_err("Suspend not allowed when EDAC is enabled.\n");
> +
> +	return -EPERM;
> +}
> +
> +static const struct dev_pm_ops altr_sdram_pm_ops = {
> +	.prepare = altr_sdram_prepare,
> +};
> +#endif
> +
>  static struct platform_driver altr_sdram_edac_driver = {
>  	.probe = altr_sdram_probe,
>  	.remove = altr_sdram_remove,
>  	.driver = {
>  		.name = "altr_sdram_edac",
> +#ifdef CONFIG_PM
> +		.pm = &altr_sdram_pm_ops,
> +#endif
>  		.of_match_table = altr_sdram_ctrl_of_match,
>  	},
>  };
> -- 
> 2.3.5
> 
> -- 
> Regards/Gruss,
>     Boris.
> 
> ECO tip #101: Trim your mails when you reply.
> --
>