[PATCH] spi: spi-s3c64xx: Fix system resume support

[PATCH] spi: spi-s3c64xx: Fix system resume support

[Marek Szyprowski]

Since Linux v4.10 release (commit 1d9174fbc55e "PM / Runtime: Defer
resuming of the device in pm_runtime_force_resume()"),
pm_runtime_force_resume() function doesn't runtime resume device if it was
not runtime active before system suspend. Thus, driver should not do any
register access after pm_runtime_force_resume() without checking the
runtime status of the device. To fix this issue, simply move
s3c64xx_spi_hwinit() call to s3c64xx_spi_runtime_resume() to ensure that
hardware is always properly initialized. This fixes Synchronous external
abort issue on system suspend/resume cycle on newer Exynos SoCs.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
CC: <stable@vger.kernel.org> # 4.10.x: 1c75862d8e5a spi: spi-s3c64xx: Remove unused s3c64xx_spi_hwinit()
CC: <stable@vger.kernel.org> # 4.10.x
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Andi Shyti <andi@etezian.org>
---
Resend reason: added cc: stable, reviewed and acked tags
---
 drivers/spi/spi-s3c64xx.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index f55dc78957ad..7b7151ec14c8 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -1292,8 +1292,6 @@ static int s3c64xx_spi_resume(struct device *dev)
 	if (ret < 0)
 		return ret;
 
-	s3c64xx_spi_hwinit(sdd);
-
 	return spi_master_resume(master);
 }
 #endif /* CONFIG_PM_SLEEP */
@@ -1331,6 +1329,8 @@ static int s3c64xx_spi_runtime_resume(struct device *dev)
 	if (ret != 0)
 		goto err_disable_src_clk;
 
+	s3c64xx_spi_hwinit(sdd);
+
 	return 0;
 
 err_disable_src_clk:
-- 
2.17.0

Re: [PATCH] spi: spi-s3c64xx: Fix system resume support

[Mark Brown]

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On Thu, May 17, 2018 at 12:15:08PM +0200, Marek Szyprowski wrote:

> Resend reason: added cc: stable, reviewed and acked tags

Please don't resend so quickly for stuff like this, it just makes noise
- stable doesn't need to be CCed on e-mails.

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Re: [PATCH] spi: spi-s3c64xx: Fix system resume support

[Krzysztof Kozlowski]

On Thu, May 17, 2018 at 6:41 PM, Mark Brown <broonie@kernel.org> wrote:
> On Thu, May 17, 2018 at 12:15:08PM +0200, Marek Szyprowski wrote:
>
>> Resend reason: added cc: stable, reviewed and acked tags
>
> Please don't resend so quickly for stuff like this, it just makes noise
> - stable doesn't need to be CCed on e-mails.

Hi Mark,

The point of resend was to add the specific cc-stable tags with a
prerequisite for backporting:
    CC: <stable@vger.kernel.org> # 4.10.x: 1c75862d8e5a spi:
spi-s3c64xx: Remove unused s3c64xx_spi_hwinit()
    CC: <stable@vger.kernel.org> # 4.10.x
Unfortunately I saw that these did not end up in patch you committed.
Mentioning required commit is, I think, quite helpful for stable guys.

Best regards,
Krzysztof

Re: [PATCH] spi: spi-s3c64xx: Fix system resume support

[Mark Brown]

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On Fri, May 18, 2018 at 07:33:03AM +0200, Krzysztof Kozlowski wrote:

> The point of resend was to add the specific cc-stable tags with a
> prerequisite for backporting:
>     CC: <stable@vger.kernel.org> # 4.10.x: 1c75862d8e5a spi:
> spi-s3c64xx: Remove unused s3c64xx_spi_hwinit()
>     CC: <stable@vger.kernel.org> # 4.10.x

> Unfortunately I saw that these did not end up in patch you committed.
> Mentioning required commit is, I think, quite helpful for stable guys.

If you want to mention the commit being fixed then use a Fixes: tag.  I
was complaining because I'd already applied the commit before that got
resent so I had to try to figure out what was going on with it.

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