Hi Adrian,
On 20/06/2017 09:39, Adrian Hunter wrote:
> On 16/06/17 10:29, Quentin Schulz wrote:
>> This adds deepest (Backup+Self-Refresh) PM support to the ATMEL SAMA5D2
>> SoC's SDHCI controller.
>>
>> When resuming from deepest state, it is required to restore preset
>> registers as the registers are lost since VDD core has been shut down
>> when entering deepest state on the SAMA5D2. The clocks need to be
>> reconfigured as well.
>>
>> The other registers and init process are taken care of by the SDHCI
>> core.
>>
>> Signed-off-by: Quentin Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxx>
>> ---
>> drivers/mmc/host/sdhci-of-at91.c | 34 ++++++++++++++++++++++++++++++++--
>> 1 file changed, 32 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c
>> index fb8c6011f13d..300513fc1068 100644
>> --- a/drivers/mmc/host/sdhci-of-at91.c
>> +++ b/drivers/mmc/host/sdhci-of-at91.c
>> @@ -207,6 +207,37 @@ static int sdhci_at91_set_clks_presets(struct device *dev)
>> }
>>
>> #ifdef CONFIG_PM
>
> Should be CONFIG_PM_SLEEP for suspend / resume callbacks.
>
So I let this CONFIG_PM around the runtime_suspend/resume but put
another CONFIG_PM_SLEEP around the suspend/resume functions?
>> +static int sdhci_at91_suspend(struct device *dev)
>> +{
>> + struct sdhci_host *host = dev_get_drvdata(dev);
>> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> + struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
>> + int ret;
>> +
>> + ret = sdhci_suspend_host(host);
>> +
>> + if (host->runtime_suspended)
>> + return ret;
>
> Suspending while runtime suspended seems like a bad idea. Have you
> considered just adding sdhci_at91_set_clks_presets() to
> sdhci_at91_runtime_resume()?
>
Adding sdhci_at91_set_clks_presets() to runtime_resume() seems a bad
idea as well. You don't need to recompute the clock rate, set it and set
the presets registers each time you do a runtime_resume. As the
runtime_pm of sdhci has a quite aggressive policy of activation, this
seems like a bad idea on the optimization side.
Thanks,
Quentin
>> +
>> + clk_disable_unprepare(priv->gck);
>> + clk_disable_unprepare(priv->hclock);
>> + clk_disable_unprepare(priv->mainck);
>> +
>> + return ret;
>> +}
>> +
>> +static int sdhci_at91_resume(struct device *dev)
>> +{
>> + struct sdhci_host *host = dev_get_drvdata(dev);
>> + int ret;
>> +
>> + ret = sdhci_at91_set_clks_presets(dev);
>> + if (ret)
>> + return ret;
>> +
>> + return sdhci_resume_host(host);
>> +}
>> +
>> static int sdhci_at91_runtime_suspend(struct device *dev)
>> {
>> struct sdhci_host *host = dev_get_drvdata(dev);
>> @@ -256,8 +287,7 @@ static int sdhci_at91_runtime_resume(struct device *dev)
>> #endif /* CONFIG_PM */
>>
>> static const struct dev_pm_ops sdhci_at91_dev_pm_ops = {
>> - SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
>> - pm_runtime_force_resume)
>> + SET_SYSTEM_SLEEP_PM_OPS(sdhci_at91_suspend, sdhci_at91_resume)
>> SET_RUNTIME_PM_OPS(sdhci_at91_runtime_suspend,
>> sdhci_at91_runtime_resume,
>> NULL)
>>
>
--
Quentin Schulz, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
