[PATCH 2/2] mmc: tmio: Make sure the PM domain is 'started' while probing

From: Ulf Hansson <ulf.hansson@linaro.org>
To: linux-mmc@vger.kernel.org, Ulf Hansson <ulf.hansson@linaro.org>,
	Masahiro Yamada <yamada.masahiro@socionext.com>,
	Wolfram Sang <wsa+renesas@sang-engineering.com>,
	Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ulrich Hecht <uli+renesas@fpond.eu>,
	Simon Horman <horms+renesas@verge.net.au>,
	Niklas Soderlund <niklas.soderlund@ragnatech.se>,
	Geert Uytterhoeven <geert+renesas@glider.be>
Subject: [PATCH 2/2] mmc: tmio: Make sure the PM domain is 'started' while probing
Date: Tue, 19 May 2020 17:24:45 +0200	[thread overview]
Message-ID: <20200519152445.6922-1-ulf.hansson@linaro.org> (raw)

If the tmio device is attached to a genpd (PM domain), that genpd may have
->start|stop() callback assigned to it. To make sure the device is
accessible during ->probe(), genpd's ->start() callback must be invoked,
which is currently managed by tmio_mmc_host_probe(). However, it's likely
that may be too late for some cases, as registers may be read and written
way before that point.

To fix the behaviour, let's move the call to dev_pm_domain_start() from
tmio_mmc_host_probe() into those clients that needs it. From discussions at
linux-mmc mailing list, it turned out that it should be sufficient to do
this for the SDHI renesas variants, hence the call is move to
renesas_sdhi_probe().

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
 drivers/mmc/host/renesas_sdhi_core.c | 3 +++
 drivers/mmc/host/tmio_mmc_core.c     | 2 --
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c
index ff72b381a6b3..dcba9ad35dd1 100644
--- a/drivers/mmc/host/renesas_sdhi_core.c
+++ b/drivers/mmc/host/renesas_sdhi_core.c
@@ -24,6 +24,7 @@
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
+#include <linux/pm_domain.h>
 #include <linux/mmc/host.h>
 #include <linux/mmc/slot-gpio.h>
 #include <linux/mfd/tmio.h>
@@ -905,6 +906,8 @@ int renesas_sdhi_probe(struct platform_device *pdev,
 	/* All SDHI have SDIO status bits which must be 1 */
 	mmc_data->flags |= TMIO_MMC_SDIO_STATUS_SETBITS;
 
+	dev_pm_domain_start(&pdev->dev);
+
 	ret = renesas_sdhi_clk_enable(host);
 	if (ret)
 		goto efree;
diff --git a/drivers/mmc/host/tmio_mmc_core.c b/drivers/mmc/host/tmio_mmc_core.c
index ba301fb7656b..d7fde57c78c1 100644
--- a/drivers/mmc/host/tmio_mmc_core.c
+++ b/drivers/mmc/host/tmio_mmc_core.c
@@ -39,7 +39,6 @@
 #include <linux/module.h>
 #include <linux/pagemap.h>
 #include <linux/platform_device.h>
-#include <linux/pm_domain.h>
 #include <linux/pm_qos.h>
 #include <linux/pm_runtime.h>
 #include <linux/regulator/consumer.h>
@@ -1192,7 +1191,6 @@ int tmio_mmc_host_probe(struct tmio_mmc_host *_host)
 	/* See if we also get DMA */
 	tmio_mmc_request_dma(_host, pdata);
 
-	dev_pm_domain_start(&pdev->dev);
 	pm_runtime_get_noresume(&pdev->dev);
 	pm_runtime_set_active(&pdev->dev);
 	pm_runtime_set_autosuspend_delay(&pdev->dev, 50);
-- 
2.20.1

