[PATCH 5.6 151/161] mmc: tmio: Further fixup runtime PM management at remove

From: Greg Kroah-Hartman
Date: Tue Jun 16 2020 - 11:57:08 EST


From: Ulf Hansson <ulf.hansson@xxxxxxxxxx>

commit 4bd784411aca022622e484eb262f5a0540ae732c upstream.

Before calling tmio_mmc_host_probe(), the caller is required to enable
clocks for its device, as to make it accessible when reading/writing
registers during probe.

Therefore, the responsibility to disable these clocks, in the error path of
->probe() and during ->remove(), is better managed outside
tmio_mmc_host_remove(). As a matter of fact, callers of
tmio_mmc_host_remove() already expects this to be the behaviour.

However, there's a problem with tmio_mmc_host_remove() when the Kconfig
option, CONFIG_PM, is set. More precisely, tmio_mmc_host_remove() may then
disable the clock via runtime PM, which leads to clock enable/disable
imbalance problems, when the caller of tmio_mmc_host_remove() also tries to
disable the same clocks.

To solve the problem, let's make sure tmio_mmc_host_remove() leaves the
device with clocks enabled, but also make sure to disable the IRQs, as we
normally do at ->runtime_suspend().

Reported-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Reviewed-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
Tested-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20200519152434.6867-1-ulf.hansson@xxxxxxxxxx
Tested-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/mmc/host/tmio_mmc_core.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/mmc/host/tmio_mmc_core.c
+++ b/drivers/mmc/host/tmio_mmc_core.c
@@ -1286,12 +1286,14 @@ void tmio_mmc_host_remove(struct tmio_mm
cancel_work_sync(&host->done);
cancel_delayed_work_sync(&host->delayed_reset_work);
tmio_mmc_release_dma(host);
+ tmio_mmc_disable_mmc_irqs(host, TMIO_MASK_ALL);

- pm_runtime_dont_use_autosuspend(&pdev->dev);
if (host->native_hotplug)
pm_runtime_put_noidle(&pdev->dev);
- pm_runtime_put_sync(&pdev->dev);
+
pm_runtime_disable(&pdev->dev);
+ pm_runtime_dont_use_autosuspend(&pdev->dev);
+ pm_runtime_put_noidle(&pdev->dev);
}
EXPORT_SYMBOL_GPL(tmio_mmc_host_remove);