Re: [PATCH v5 1/1] mmc: mtk-sd: reduce CIT for better performance

[Wenbin Mei (梅文彬)]

On Fri, 2023-06-09 at 01:10 +0200, Ulf Hansson wrote:
>  	 
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
>  On Tue, 6 Jun 2023 at 13:32, Wenbin Mei <wenbin.mei@xxxxxxxxxxxx>
> wrote:
> >
> > CQHCI_SSC1 indicates to CQE the polling period to use when using
> periodic
> > SEND_QUEUE_STATUS(CMD13) polling.
> > Since MSDC CQE uses msdc_hclk as ITCFVAL, so driver should use hclk
> > frequency to get the actual time.
> > The default value 0x1000 that corresponds to 150us for MediaTek
> SoCs, let's
> > decrease it to 0x40 that corresponds to 2.35us, which can improve
> the
> > performance of some eMMC devices.
> >
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > Signed-off-by: Wenbin Mei <wenbin.mei@xxxxxxxxxxxx>
> 
> Applied for next, thanks!
> 
> Kind regards
> Uffe
> 
Hi Ulf,

Sorry for the trouble.
Because the v5 version build failed, I have uploader two patches, one
is new fix patch, the other is v6 version.

If you choose the v6 version to apply, please ignore the fix patch.
Thanks!

Begards,
Wenbin

> 
> > ---
> > the previous patche link:
> > v4: 
> https://patchwork.kernel.org/project/linux-mediatek/patch/20230605121442.23622-1-wenbin.mei@xxxxxxxxxxxx/
> > v3: 
> https://patchwork.kernel.org/project/linux-mediatek/patch/20230605060107.22044-1-wenbin.mei@xxxxxxxxxxxx/
> > v2: 
> https://patchwork.kernel.org/project/linux-mediatek/patch/20230510015851.11830-1-wenbin.mei@xxxxxxxxxxxx/
> > v1: 
> https://patchwork.kernel.org/project/linux-mediatek/patch/20230419063048.10516-1-wenbin.mei@xxxxxxxxxxxx/
> > ---
> >  drivers/mmc/host/cqhci.h  |  2 ++
> >  drivers/mmc/host/mtk-sd.c | 47
> +++++++++++++++++++++++++++++++++++++++
> >  2 files changed, 49 insertions(+)
> >
> > diff --git a/drivers/mmc/host/cqhci.h b/drivers/mmc/host/cqhci.h
> > index ba9387ed90eb..e35c655edefc 100644
> > --- a/drivers/mmc/host/cqhci.h
> > +++ b/drivers/mmc/host/cqhci.h
> > @@ -23,6 +23,8 @@
> >  /* capabilities */
> >  #define CQHCI_CAP                      0x04
> >  #define CQHCI_CAP_CS                   0x10000000 /* Crypto
> Support */
> > +#define CQHCI_CAP_ITCFMUL              GENMASK(15, 12)
> > +#define
> CQHCI_ITCFMUL(x)               FIELD_GET(CQHCI_CAP_ITCFMUL, (x))
> >
> >  /* configuration */
> >  #define CQHCI_CFG                      0x08
> > diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
> > index 8ce864169986..b582f19f82f2 100644
> > --- a/drivers/mmc/host/mtk-sd.c
> > +++ b/drivers/mmc/host/mtk-sd.c
> > @@ -473,6 +473,7 @@ struct msdc_host {
> >         struct msdc_tune_para def_tune_para; /* default tune
> setting */
> >         struct msdc_tune_para saved_tune_para; /* tune result of
> CMD21/CMD19 */
> >         struct cqhci_host *cq_host;
> > +       u32 cq_ssc1_time;
> >  };
> >
> >  static const struct mtk_mmc_compatible mt2701_compat = {
> > @@ -2450,9 +2451,50 @@ static void
> msdc_hs400_enhanced_strobe(struct mmc_host *mmc,
> >         }
> >  }
> >
> > +static void msdc_cqe_cit_cal(struct msdc_host *host, u64 timer_ns)
> > +{
> > +       struct mmc_host *mmc = mmc_from_priv(host);
> > +       struct cqhci_host *cq_host = mmc->cqe_private;
> > +       u8 itcfmul;
> > +       unsigned long hclk_freq;
> > +       u64 value;
> > +
> > +       /*
> > +        * On MediaTek SoCs the MSDC controller's CQE uses
> msdc_hclk as ITCFVAL
> > +        * so we multiply/divide the HCLK frequency by ITCFMUL to
> calculate the
> > +        * Send Status Command Idle Timer (CIT) value.
> > +        */
> > +       hclk_freq = clk_get_rate(host->h_clk);
> > +       itcfmul = CQHCI_ITCFMUL(cqhci_readl(cq_host, CQHCI_CAP));
> > +       switch (itcfmul) {
> > +       case 0x0:
> > +               do_div(hclk_freq, 1000);
> > +               break;
> > +       case 0x1:
> > +               do_div(hclk_freq, 100);
> > +               break;
> > +       case 0x2:
> > +               do_div(hclk_freq, 10);
> > +               break;
> > +       case 0x3:
> > +               break;
> > +       case 0x4:
> > +               hclk_freq = hclk_freq * 10;
> > +               break;
> > +       default:
> > +               host->cq_ssc1_time = 0x40;
> > +               return;
> > +       }
> > +
> > +       value = hclk_freq * timer_ns;
> > +       do_div(value, 1000000000);
> > +       host->cq_ssc1_time = value;
> > +}
> > +
> >  static void msdc_cqe_enable(struct mmc_host *mmc)
> >  {
> >         struct msdc_host *host = mmc_priv(mmc);
> > +       struct cqhci_host *cq_host = mmc->cqe_private;
> >
> >         /* enable cmdq irq */
> >         writel(MSDC_INT_CMDQ, host->base + MSDC_INTEN);
> > @@ -2462,6 +2504,9 @@ static void msdc_cqe_enable(struct mmc_host
> *mmc)
> >         msdc_set_busy_timeout(host, 20 * 1000000000ULL, 0);
> >         /* default read data timeout 1s */
> >         msdc_set_timeout(host, 1000000000ULL, 0);
> > +
> > +       /* Set the send status command idle timer */
> > +       cqhci_writel(cq_host, host->cq_ssc1_time, CQHCI_SSC1);
> >  }
> >
> >  static void msdc_cqe_disable(struct mmc_host *mmc, bool recovery)
> > @@ -2803,6 +2848,8 @@ static int msdc_drv_probe(struct
> platform_device *pdev)
> >                 /* cqhci 16bit length */
> >                 /* 0 size, means 65536 so we don't have to -1 here
> */
> >                 mmc->max_seg_size = 64 * 1024;
> > +               /* Reduce CIT to 0x40 that corresponds to 2.35us */
> > +               msdc_cqe_cit_cal(host, 2350);
> >         }
> >
> >         ret = devm_request_irq(&pdev->dev, host->irq, msdc_irq,
> > --
> > 2.25.1
> >