Re: [PATCH v2 2/2] mmc: dw_mmc-rockchip: parse rockchip,desired-num-phases from DT

[Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>]

Hi Jaehoon,

On 2017/5/18 10:20, Jaehoon Chung wrote:
> Hi Shawn,
>
> On 05/16/2017 03:28 PM, Shawn Lin wrote:
> > Currently we unconditionally do tuning for each degree, which
> > costs 900ms for each boot and resume.
> >
> > May someone argue that this is a question of accuracy VS time. But I
> > would say it's a trick of how we need to do decision for our boards.
> > If we don't care the time we spend at all, we could definitely do tuning
> > for each degree. But when we need to improve the user experience, for
> > instance, speed up resuming from S3, we should also have the right to
> > do that. This patch add parsing "rockchip,desired-num-phases", for folks
> > to specify the number of doing tuning. If not specified, 360 will be used
> > as before.
> >
> > Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
>
> Will pick this patch with [PATCH 1/2] after getting acked tags from DT guys.

patch 1 was acked by Rob, so I assume these two are material for 4.13?

> Best Regards,
> Jaehoon Chung
>
> > ---
> >
> > Changes in v2:
> > - rename property to rockchip,desired-num-phases
> >
> >   drivers/mmc/host/dw_mmc-rockchip.c | 48 ++++++++++++++++++++++++--------------
> >   1 file changed, 30 insertions(+), 18 deletions(-)
> >
> > diff --git a/drivers/mmc/host/dw_mmc-rockchip.c b/drivers/mmc/host/dw_mmc-rockchip.c
> > index 372fb6e..a3f1c2b 100644
> > --- a/drivers/mmc/host/dw_mmc-rockchip.c
> > +++ b/drivers/mmc/host/dw_mmc-rockchip.c
> > @@ -25,6 +25,7 @@ struct dw_mci_rockchip_priv_data {
> >   	struct clk		*drv_clk;
> >   	struct clk		*sample_clk;
> >   	int			default_sample_phase;
> > +	int			num_phases;
> >   };
> >   
> >   static void dw_mci_rk3288_set_ios(struct dw_mci *host, struct mmc_ios *ios)
> > @@ -133,8 +134,8 @@ static void dw_mci_rk3288_set_ios(struct dw_mci *host, struct mmc_ios *ios)
> >   	}
> >   }
> >   
> > -#define NUM_PHASES			360
> > -#define TUNING_ITERATION_TO_PHASE(i)	(DIV_ROUND_UP((i) * 360, NUM_PHASES))
> > +#define TUNING_ITERATION_TO_PHASE(i, num_phases) \
> > +		(DIV_ROUND_UP((i) * 360, num_phases))
> >   
> >   static int dw_mci_rk3288_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
> >   {
> > @@ -159,13 +160,15 @@ static int dw_mci_rk3288_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
> >   		return -EIO;
> >   	}
> >   
> > -	ranges = kmalloc_array(NUM_PHASES / 2 + 1, sizeof(*ranges), GFP_KERNEL);
> > +	ranges = kmalloc_array(priv->num_phases / 2 + 1,
> > +			       sizeof(*ranges), GFP_KERNEL);
> >   	if (!ranges)
> >   		return -ENOMEM;
> >   
> >   	/* Try each phase and extract good ranges */
> > -	for (i = 0; i < NUM_PHASES; ) {
> > -		clk_set_phase(priv->sample_clk, TUNING_ITERATION_TO_PHASE(i));
> > +	for (i = 0; i < priv->num_phases; ) {
> > +		clk_set_phase(priv->sample_clk,
> > +			      TUNING_ITERATION_TO_PHASE(i, priv->num_phases));
> >   
> >   		v = !mmc_send_tuning(mmc, opcode, NULL);
> >   
> > @@ -179,7 +182,7 @@ static int dw_mci_rk3288_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
> >   		if (v) {
> >   			ranges[range_count-1].end = i;
> >   			i++;
> > -		} else if (i == NUM_PHASES - 1) {
> > +		} else if (i == priv->num_phases - 1) {
> >   			/* No extra skipping rules if we're at the end */
> >   			i++;
> >   		} else {
> > @@ -188,11 +191,11 @@ static int dw_mci_rk3288_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
> >   			 * one since testing bad phases is slow.  Skip
> >   			 * 20 degrees.
> >   			 */
> > -			i += DIV_ROUND_UP(20 * NUM_PHASES, 360);
> > +			i += DIV_ROUND_UP(20 * priv->num_phases, 360);
> >   
> >   			/* Always test the last one */
> > -			if (i >= NUM_PHASES)
> > -				i = NUM_PHASES - 1;
> > +			if (i >= priv->num_phases)
> > +				i = priv->num_phases - 1;
> >   		}
> >   
> >   		prev_v = v;
> > @@ -210,7 +213,7 @@ static int dw_mci_rk3288_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
> >   		range_count--;
> >   	}
> >   
> > -	if (ranges[0].start == 0 && ranges[0].end == NUM_PHASES - 1) {
> > +	if (ranges[0].start == 0 && ranges[0].end == priv->num_phases - 1) {
> >   		clk_set_phase(priv->sample_clk, priv->default_sample_phase);
> >   		dev_info(host->dev, "All phases work, using default phase %d.",
> >   			 priv->default_sample_phase);
> > @@ -222,7 +225,7 @@ static int dw_mci_rk3288_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
> >   		int len = (ranges[i].end - ranges[i].start + 1);
> >   
> >   		if (len < 0)
> > -			len += NUM_PHASES;
> > +			len += priv->num_phases;
> >   
> >   		if (longest_range_len < len) {
> >   			longest_range_len = len;
> > @@ -230,25 +233,30 @@ static int dw_mci_rk3288_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
> >   		}
> >   
> >   		dev_dbg(host->dev, "Good phase range %d-%d (%d len)\n",
> > -			TUNING_ITERATION_TO_PHASE(ranges[i].start),
> > -			TUNING_ITERATION_TO_PHASE(ranges[i].end),
> > +			TUNING_ITERATION_TO_PHASE(ranges[i].start,
> > +						  priv->num_phases),
> > +			TUNING_ITERATION_TO_PHASE(ranges[i].end,
> > +						  priv->num_phases),
> >   			len
> >   		);
> >   	}
> >   
> >   	dev_dbg(host->dev, "Best phase range %d-%d (%d len)\n",
> > -		TUNING_ITERATION_TO_PHASE(ranges[longest_range].start),
> > -		TUNING_ITERATION_TO_PHASE(ranges[longest_range].end),
> > +		TUNING_ITERATION_TO_PHASE(ranges[longest_range].start,
> > +					  priv->num_phases),
> > +		TUNING_ITERATION_TO_PHASE(ranges[longest_range].end,
> > +					  priv->num_phases),
> >   		longest_range_len
> >   	);
> >   
> >   	middle_phase = ranges[longest_range].start + longest_range_len / 2;
> > -	middle_phase %= NUM_PHASES;
> > +	middle_phase %= priv->num_phases;
> >   	dev_info(host->dev, "Successfully tuned phase to %d\n",
> > -		 TUNING_ITERATION_TO_PHASE(middle_phase));
> > +		 TUNING_ITERATION_TO_PHASE(middle_phase, priv->num_phases));
> >   
> >   	clk_set_phase(priv->sample_clk,
> > -		      TUNING_ITERATION_TO_PHASE(middle_phase));
> > +		      TUNING_ITERATION_TO_PHASE(middle_phase,
> > +						priv->num_phases));
> >   
> >   free:
> >   	kfree(ranges);
> > @@ -264,6 +272,10 @@ static int dw_mci_rk3288_parse_dt(struct dw_mci *host)
> >   	if (!priv)
> >   		return -ENOMEM;
> >   
> > +	if (of_property_read_u32(np, "rockchip,desired-num-phases",
> > +					&priv->num_phases))
> > +		priv->num_phases = 360;
> > +
> >   	if (of_property_read_u32(np, "rockchip,default-sample-phase",
> >   					&priv->default_sample_phase))
> >   		priv->default_sample_phase = 0;
>
>
> _______________________________________________
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> Linux-rockchip@xxxxxxxxxxxxxxxxxxx
> http://lists.infradead.org/mailman/listinfo/linux-rockchip

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