Re: [PATCH V1 1/2] mmc: sdhci-msm: Add interconnect bandwidth scaling support

[ppvk]

Hi Sibi,

Thanks for the review!!

On 2020-06-03 17:22, Sibi Sankar wrote:
> Hey Pradeep,
> Thanks for the patch.
>
> On 2020-06-03 14:39, Pradeep P V K wrote:
> > Interconnect bandwidth scaling support is now added as a
> > part of OPP [1]. So, make sure interconnect driver is ready
> > before handling interconnect scaling.
> >
> > This change is based on
> > [1] [Patch v8] Introduce OPP bandwidth bindings
> > (https://lkml.org/lkml/2020/5/12/493)
> >
> > [2] [Patch v3] mmc: sdhci-msm: Fix error handling
> > for dev_pm_opp_of_add_table()
> > (https://lkml.org/lkml/2020/5/5/491)
> >
> > Signed-off-by: Pradeep P V K <ppvk@xxxxxxxxxxxxxx>
> > ---
> >  drivers/mmc/host/sdhci-msm.c | 16 ++++++++++++++++
> >  1 file changed, 16 insertions(+)
> >
> > diff --git a/drivers/mmc/host/sdhci-msm.c 
> > b/drivers/mmc/host/sdhci-msm.c
> > index b277dd7..bf95484 100644
> > --- a/drivers/mmc/host/sdhci-msm.c
> > +++ b/drivers/mmc/host/sdhci-msm.c
> > @@ -14,6 +14,7 @@
> >  #include <linux/slab.h>
> >  #include <linux/iopoll.h>
> >  #include <linux/regulator/consumer.h>
> > +#include <linux/interconnect.h>
> >
> >  #include "sdhci-pltfm.h"
> >  #include "cqhci.h"
> > @@ -1999,6 +2000,7 @@ static int sdhci_msm_probe(struct 
> > platform_device *pdev)
> >  	struct sdhci_pltfm_host *pltfm_host;
> >  	struct sdhci_msm_host *msm_host;
> >  	struct clk *clk;
> > +	struct icc_path *sdhc_path;
> >  	int ret;
> >  	u16 host_version, core_minor;
> >  	u32 core_version, config;
> > @@ -2070,6 +2072,20 @@ static int sdhci_msm_probe(struct 
> > platform_device *pdev)
> >  	}
> >  	msm_host->bulk_clks[0].clk = clk;
> >
> > +	/* Make sure that ICC driver is ready for interconnect bandwdith
> > +	 * scaling before registering the device for OPP.
> > +	 */
> > +	sdhc_path = of_icc_get(&pdev->dev, NULL);
> > +	ret = PTR_ERR_OR_ZERO(sdhc_path);
> > +	if (ret) {
> > +		if (ret == -EPROBE_DEFER)
> > +			dev_info(&pdev->dev, "defer icc path: %d\n", ret);
> > +		else
> > +			dev_err(&pdev->dev, "failed to get icc path:%d\n", ret);
> > +		goto bus_clk_disable;
> > +	}
> > +	icc_put(sdhc_path);
>
> ret = dev_pm_opp_of_find_icc_paths(&pdev->dev, NULL);
>
> since there are multiple paths
> described in the bindings you
> should use ^^ instead and you
> can drop temporary path as well.
Ok. of_icc_get() used above is only to test if ICC driver is ready or 
not. I'm not
really using the multiple paths here. Anyhow i will use 
dev_pm_opp_of_find_icc_paths()
to get rid of some extra lines of code.

> > +
> >  	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);