Re: [PATCH 2/2] davinci: MMC: updates to suspend/resume implementation

[Kevin Hilman]

Janakiram Sistla <janakiram.sistla@xxxxxxxxx> writes:

> On 12/17/09, Chaithrika U S <chaithrika@xxxxxx> wrote:
>> Improve the suspend and resume callbacks in DaVinci MMC
>> host controller driver.
>
> [Ram] I came cross in the mailing some days back that "direct"
> .suspend and .resume calls will stop being supported.Is This
> true??This patch does require a migration then again.

Yes, this patch (or an additional patch) will have to update the
MMC driver to use dev_pm_ops.

See this commit in Linus' tree where I converted the smc91x driver.
Something like this will nee dto be done for this driver as well.

Kevin

commit 9f950f72e57fe4bf9b16ace67e4cc5ffcee79d00
Author: Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx>
Date:   Tue Nov 24 12:57:47 2009 +0000

    NET: smc91x: convert to dev_pm_ops
    
    Convert smc91x driver from legacy PM hooks over to using dev_pm_ops.
    
    Tested on OMAP3 platform.
    
    Signed-off-by: Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx>
    Acked-by: Nicolas Pitre <nico@xxxxxxxxxxx>
    Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>

>> Tested on DA850/OMAP-L138 EVM. This testing requires patches
>> which add suspend-to-RAM support to DA850/OMAP-L138 SoC[1].
>>
>> [1]http://linux.davincidsp.com/pipermail/davinci-linux-open-source/
>> 2009-September/016118.html
>>
>> Signed-off-by: Chaithrika U S <chaithrika@xxxxxx>
>> ---
>> Applies to Linus' kernel tree.
>>
>>  drivers/mmc/host/davinci_mmc.c |   31 +++++++++++++++++++++++++++++--
>>  1 files changed, 29 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/mmc/host/davinci_mmc.c b/drivers/mmc/host/davinci_mmc.c
>> index 25645bf..7d05cc1 100644
>> --- a/drivers/mmc/host/davinci_mmc.c
>> +++ b/drivers/mmc/host/davinci_mmc.c
>> @@ -170,6 +170,7 @@ struct mmc_davinci_host {
>>  #define DAVINCI_MMC_DATADIR_READ       1
>>  #define DAVINCI_MMC_DATADIR_WRITE      2
>>        unsigned char data_dir;
>> +       unsigned char suspended;
>>
>>        /* buffer is used during PIO of one scatterlist segment, and
>>         * is updated along with buffer_bytes_left.  bytes_left applies
>> @@ -1300,15 +1301,41 @@ static int __exit davinci_mmcsd_remove(struct platform_device *pdev)
>>  static int davinci_mmcsd_suspend(struct platform_device *pdev, pm_message_t msg)
>>  {
>>        struct mmc_davinci_host *host = platform_get_drvdata(pdev);
>> +       int ret;
>>
>> -       return mmc_suspend_host(host->mmc, msg);
>> +       mmc_host_enable(host->mmc);
>> +       ret = mmc_suspend_host(host->mmc, msg);
>> +       if (!ret) {
>> +               writel(0, host->base + DAVINCI_MMCIM);
>> +               mmc_davinci_reset_ctrl(host, 1);
>> +               mmc_host_disable(host->mmc);
>> +               clk_disable(host->clk);
>> +               host->suspended = 1;
>> +       } else {
>> +               host->suspended = 0;
>> +               mmc_host_disable(host->mmc);
>> +       }
>> +
>> +       return ret;
>>  }
>>
>>  static int davinci_mmcsd_resume(struct platform_device *pdev)
>>  {
>>        struct mmc_davinci_host *host = platform_get_drvdata(pdev);
>> +       int ret;
>>
>> -       return mmc_resume_host(host->mmc);
>> +       if (!host->suspended)
>> +               return 0;
>> +
>> +       clk_enable(host->clk);
>> +       mmc_host_enable(host->mmc);
>> +
>> +       mmc_davinci_reset_ctrl(host, 0);
>> +       ret = mmc_resume_host(host->mmc);
>> +       if (!ret)
>> +               host->suspended = 0;
>> +
>> +       return ret;
>>  }
>>  #else
>>  #define davinci_mmcsd_suspend  NULL
>> --
>> 1.5.6
>>
>> --
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