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

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Message-ID: <15efa375-cf1e-b793-1d3e-29ca0a547522@codeaurora.org>
Date:   Wed, 29 Apr 2020 19:39:03 +0530
From:   Rajendra Nayak <rnayak@...eaurora.org>
To:     Ulf Hansson <ulf.hansson@...aro.org>
Cc:     Viresh Kumar <viresh.kumar@...aro.org>,
        Stephen Boyd <sboyd@...nel.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Andy Gross <agross@...nel.org>,
        linux-arm-msm <linux-arm-msm@...r.kernel.org>,
        DTML <devicetree@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Matthias Kaehlcke <mka@...omium.org>,
        Pradeep P V K <ppvk@...eaurora.org>,
        Veerabhadrarao Badiganti <vbadigan@...eaurora.org>,
        "linux-mmc@...r.kernel.org" <linux-mmc@...r.kernel.org>
Subject: Re: [PATCH v3 09/17] mmc: sdhci-msm: Fix error handling for
 dev_pm_opp_of_add_table()


On 4/28/2020 11:59 PM, Ulf Hansson wrote:
> On Tue, 28 Apr 2020 at 15:39, Rajendra Nayak <rnayak@...eaurora.org> wrote:
>>
>> 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
> 
> Is this a standalone patch that I queue up via my mmc tree?

Hi Ulf, yes, its a standalone patch which applies on top of the one
you already have in your tree. No other dependencies.

> 
> Kind regards
> Uffe
> 
>> ---
>>   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);
>> --
>> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
>> of Code Aurora Forum, hosted by The Linux Foundation

-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation