lkml.org 
[lkml]   [2020]   [Oct]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH] spi: imx: Revert "spi: imx: enable runtime pm support"
On Fri, Oct 09, 2020 at 09:48:29AM +0200, Christian Eggers wrote:
> Hi Sascha,
>
> On Friday, 9 October 2020, 09:39:44 CEST, Sascha Hauer wrote:
> > On Fri, Oct 09, 2020 at 06:27:38AM +0200, Christian Eggers wrote:
> > > This reverts commit 525c9e5a32bd7951eae3f06d9d077fea51718a6c.
> > >
> > > If CONFIG_PM is disabled, the system completely freezes on probe as
> > > nothing enables the clock of the SPI peripheral.
> >
> > Instead of reverting it, why not just fix it?
> I expect that 5.9 will be released soon. I think that in this late stage
> reverting is more safe than fixing...
>
> > Normally the device should be brought to active state manually in probe
> > before pm_runtime takes over, then CONFIG_PM disabled doesn't hurt.
> > Using pm_runtime to put the device to active state initially has the
> > problem you describe.
> Thanks for the hint. I've no experience in runtime power management. If you
> could provide a patch against the current version, I can make a quick test. I
> can also try to fix it myself, but this will take until next week.

Here we go. The patch basically works, but I am also not very confident
with pm_runtime, so please have a close look ;)

Sascha

-------------------------------8<--------------------------------

From 6c584eb8a2fbff46bf8bbebae6c10609c169309b Mon Sep 17 00:00:00 2001
From: Sascha Hauer <s.hauer@pengutronix.de>
Date: Mon, 12 Oct 2020 15:59:50 +0200
Subject: [PATCH] spi: imx: fix runtime pm support for !CONFIG_PM

525c9e5a32bd introduced pm_runtime support for the i.MX SPI driver. With
this pm_runtime is used to bring up the clocks initially. When CONFIG_PM
is disabled the clocks are no longer enabled and the driver doesn't work
anymore. Fix this by enabling the clocks in the probe function and
telling pm_runtime that the device is active using
pm_runtime_set_active().

Fixes: 525c9e5a32bd spi: imx: enable runtime pm support
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
drivers/spi/spi-imx.c | 23 +++++++++++++++--------
1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 38a5f1304cec..c796e937dc6a 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -1674,15 +1674,18 @@ static int spi_imx_probe(struct platform_device *pdev)
goto out_master_put;
}

- pm_runtime_enable(spi_imx->dev);
+ ret = clk_prepare_enable(spi_imx->clk_per);
+ if (ret)
+ goto out_master_put;
+
+ ret = clk_prepare_enable(spi_imx->clk_ipg);
+ if (ret)
+ goto out_put_per;
+
pm_runtime_set_autosuspend_delay(spi_imx->dev, MXC_RPM_TIMEOUT);
pm_runtime_use_autosuspend(spi_imx->dev);
-
- ret = pm_runtime_get_sync(spi_imx->dev);
- if (ret < 0) {
- dev_err(spi_imx->dev, "failed to enable clock\n");
- goto out_runtime_pm_put;
- }
+ pm_runtime_set_active(spi_imx->dev);
+ pm_runtime_enable(spi_imx->dev);

spi_imx->spi_clk = clk_get_rate(spi_imx->clk_per);
/*
@@ -1719,8 +1722,12 @@ static int spi_imx_probe(struct platform_device *pdev)

out_runtime_pm_put:
pm_runtime_dont_use_autosuspend(spi_imx->dev);
- pm_runtime_put_sync(spi_imx->dev);
+ pm_runtime_set_suspended(&pdev->dev);
pm_runtime_disable(spi_imx->dev);
+
+ clk_disable_unprepare(spi_imx->clk_ipg);
+out_put_per:
+ clk_disable_unprepare(spi_imx->clk_per);
out_master_put:
spi_master_put(master);

--
2.28.0

--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
\
 
 \ /
  Last update: 2020-10-12 16:09    [W:0.110 / U:0.804 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site