linux-kernel - [PATCH v3 09/17] mmc: sdhci-msm: Fix error handling for dev_pm_opp_of_add

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Message-Id: <1588080785-6812-10-git-send-email-rnayak@codeaurora.org>
Date:   Tue, 28 Apr 2020 19:02:57 +0530
From:   Rajendra Nayak <rnayak@...eaurora.org>
To:     viresh.kumar@...aro.org, sboyd@...nel.org,
        bjorn.andersson@...aro.org, agross@...nel.org
Cc:     linux-arm-msm@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, mka@...omium.org,
        Rajendra Nayak <rnayak@...eaurora.org>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        Pradeep P V K <ppvk@...eaurora.org>,
        Veerabhadrarao Badiganti <vbadigan@...eaurora.org>,
        linux-mmc@...r.kernel.org
Subject: [PATCH v3 09/17] mmc: sdhci-msm: Fix error handling for dev_pm_opp_of_add_table()

Even though specifying OPP's in device tree is optional, ignoring all errors
reported by dev_pm_opp_of_add_table() means we can't distinguish between a
missing OPP table and a wrong/buggy OPP table. While missing OPP table
(dev_pm_opp_of_add_table() returns a -ENODEV in such case) can be ignored,
a wrong/buggy OPP table in device tree should make the driver error out.

while we fix that, lets also fix the variable names for opp/opp_table to
avoid confusion and name them opp_table/has_opp_table instead.

Suggested-by: Matthias Kaehlcke <matthias@...omium.org>
Signed-off-by: Rajendra Nayak <rnayak@...eaurora.org>
Cc: Ulf Hansson <ulf.hansson@...aro.org>
Cc: Pradeep P V K <ppvk@...eaurora.org>
Cc: Veerabhadrarao Badiganti <vbadigan@...eaurora.org>
Cc: linux-mmc@...r.kernel.org
---
 drivers/mmc/host/sdhci-msm.c | 27 ++++++++++++++++-----------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index 8a055dd..97758fa 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -244,8 +244,8 @@ struct sdhci_msm_host {
 	struct clk_bulk_data bulk_clks[4]; /* core, iface, cal, sleep clocks */
 	unsigned long clk_rate;
 	struct mmc_host *mmc;
-	struct opp_table *opp;
-	bool opp_table;
+	struct opp_table *opp_table;
+	bool has_opp_table;
 	bool use_14lpp_dll_reset;
 	bool tuning_done;
 	bool calibration_done;
@@ -1967,15 +1967,20 @@ static int sdhci_msm_probe(struct platform_device *pdev)
 	}
 	msm_host->bulk_clks[0].clk = clk;
 
-	msm_host->opp = dev_pm_opp_set_clkname(&pdev->dev, "core");
-	if (IS_ERR(msm_host->opp)) {
-		ret = PTR_ERR(msm_host->opp);
+	msm_host->opp_table = dev_pm_opp_set_clkname(&pdev->dev, "core");
+	if (IS_ERR(msm_host->opp_table)) {
+		ret = PTR_ERR(msm_host->opp_table);
 		goto bus_clk_disable;
 	}
 
 	/* OPP table is optional */
-	if (!dev_pm_opp_of_add_table(&pdev->dev))
-		msm_host->opp_table = true;
+	ret = dev_pm_opp_of_add_table(&pdev->dev);
+	if (!ret) {
+		msm_host->has_opp_table = true;
+	} else if (ret != -ENODEV) {
+		dev_err(&pdev->dev, "Invalid OPP table in Device tree\n");
+		goto opp_cleanup;
+	}
 
 	/* Vote for maximum clock rate for maximum performance */
 	ret = dev_pm_opp_set_rate(&pdev->dev, INT_MAX);
@@ -2133,9 +2138,9 @@ static int sdhci_msm_probe(struct platform_device *pdev)
 	clk_bulk_disable_unprepare(ARRAY_SIZE(msm_host->bulk_clks),
 				   msm_host->bulk_clks);
 opp_cleanup:
-	if (msm_host->opp_table)
+	if (msm_host->has_opp_table)
 		dev_pm_opp_of_remove_table(&pdev->dev);
-	dev_pm_opp_put_clkname(msm_host->opp);
+	dev_pm_opp_put_clkname(msm_host->opp_table);
 bus_clk_disable:
 	if (!IS_ERR(msm_host->bus_clk))
 		clk_disable_unprepare(msm_host->bus_clk);
@@ -2154,9 +2159,9 @@ static int sdhci_msm_remove(struct platform_device *pdev)
 
 	sdhci_remove_host(host, dead);
 
-	if (msm_host->opp_table)
+	if (msm_host->has_opp_table)
 		dev_pm_opp_of_remove_table(&pdev->dev);
-	dev_pm_opp_put_clkname(msm_host->opp);
+	dev_pm_opp_put_clkname(msm_host->opp_table);
 	pm_runtime_get_sync(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_put_noidle(&pdev->dev);
-- 
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