Thread (30 messages) 30 messages, 5 authors, 2016-02-22
STALE3750d

Re: [PATCH 1/7] mmc: omap_hsmmc: Fix PM regression with deferred probe for pm_runtime_reinit

From: Ulf Hansson <hidden>
Date: 2016-02-11 10:18:34
Also in: linux-arm-kernel, linux-i2c, linux-mmc, linux-omap, linux-serial

On 11 February 2016 at 00:02, Tony Lindgren [off-list ref] wrote:
Commit 5de85b9d57ab ("PM / runtime: Re-init runtime PM states at probe
error and driver unbind") introduced pm_runtime_reinit() that is used
to reinitialize PM runtime after -EPROBE_DEFER. This allows shutting
down the device after a failed probe.

However, for drivers using pm_runtime_use_autosuspend() this can cause
a state where suspend callback is never called after -EPROBE_DEFER.
On the following device driver probe, hardware state is different from
the PM runtime state causing omap_device to produce the following
error:

omap_device_enable() called from invalid state 1

And with omap_device and omap hardware being picky for PM, this will
block any deeper idle states in hardware.

The solution is to fix the drivers to follow the PM runtime documentation:

1. For sections of code that needs the device disabled, use
   pm_runtime_put_sync_suspend() if pm_runtime_set_autosuspend() has
   been set.

2. For driver exit code, use pm_runtime_dont_use_autosuspend() before
   pm_runtime_put_sync() if pm_runtime_use_autosuspend() has been
   set.

Fixes: 5de85b9d57ab ("PM / runtime: Re-init runtime PM states at probe
error and driver unbind")
Cc: linux-mmc@vger.kernel.org
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Nishanth Menon <nm@ti.com>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Ulf Hansson <redacted>
Cc: Tero Kristo <redacted>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---

Ulf, I'd like to merge this along with other related fixes via the
ARM SoC tree if no objections, please review and ack if this look OK
to you.
I have some other omap_hsmmc patches queued for 4.6, so I prefer to
send this via my mmc tree.

I guess that's okay as well!?
quoted hunk ↗ jump to hunk
---
 drivers/mmc/host/omap_hsmmc.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index b6639ea..32bc112 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -1247,7 +1247,7 @@ static int omap_hsmmc_switch_opcond(struct omap_hsmmc_host *host, int vdd)
        int ret;

        /* Disable the clocks */
-       pm_runtime_put_sync(host->dev);
+       pm_runtime_put_sync_suspend(host->dev);
This has no effect.

The mmc core holds a runtime PM usage count for the device anyway, so
the clock won't be disabled.
Please remove this change from the patch.
quoted hunk ↗ jump to hunk
        if (host->dbclk)
                clk_disable_unprepare(host->dbclk);
@@ -2232,6 +2232,7 @@ err_irq:
                dma_release_channel(host->tx_chan);
        if (host->rx_chan)
                dma_release_channel(host->rx_chan);
+       pm_runtime_dont_use_autosuspend(host->dev);
        pm_runtime_put_sync(host->dev);
        pm_runtime_disable(host->dev);
        if (host->dbclk)
@@ -2253,6 +2254,7 @@ static int omap_hsmmc_remove(struct platform_device *pdev)
        dma_release_channel(host->tx_chan);
        dma_release_channel(host->rx_chan);

+       pm_runtime_dont_use_autosuspend(host->dev);
        pm_runtime_put_sync(host->dev);
        pm_runtime_disable(host->dev);
        device_init_wakeup(&pdev->dev, false);
@@ -2285,7 +2287,7 @@ static int omap_hsmmc_suspend(struct device *dev)
        if (host->dbclk)
                clk_disable_unprepare(host->dbclk);

-       pm_runtime_put_sync(host->dev);
+       pm_runtime_put_sync_suspend(host->dev);
This has no effect, as the PM core prevents runtime suspend during the
system PM phase.
It does so, by increasing the runtime PM usage count
(pm_runtime_get_noresume()).

Please remove this change from patch.
        return 0;
 }

--
2.7.0
Kind regards
Uffe
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