On Wed, Aug 05, 2015 at 06:38:42PM +0800, Haibo Chen wrote: > Currently we find that if a usdhc is choosed to boot system, then ROM > code will set the burst length enable bit of this usdhc as 0. > > This will make performance drop a lot if this usdhc's burst length is > configed. So this patch set back the burst_length_enable bit as 1, > which is the default value, and means burst length is enabled for INCR. > This patch should be put before patch 5 to avoid function break, right? [PATCH v4 5/6] mmc: sdhci-esdhc-imx: change default watermark level and burst length Other than that, this patch looks good to me. Regards Dong Aisheng > Signed-off-by: Haibo Chen <haibo.chen@xxxxxxxxxxxxx> > --- > drivers/mmc/host/sdhci-esdhc-imx.c | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c > index 97aa944..3334762 100644 > --- a/drivers/mmc/host/sdhci-esdhc-imx.c > +++ b/drivers/mmc/host/sdhci-esdhc-imx.c > @@ -32,6 +32,7 @@ > #include "sdhci-esdhc.h" > > #define ESDHC_CTRL_D3CD 0x08 > +#define ESDHC_BURST_LEN_EN_INCR (1 << 27) > /* VENDOR SPEC register */ > #define ESDHC_VENDOR_SPEC 0xc0 > #define ESDHC_VENDOR_SPEC_SDIO_QUIRK (1 << 1) > @@ -1165,6 +1166,21 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev) > host->quirks2 |= SDHCI_QUIRK2_PRESET_VALUE_BROKEN; > host->mmc->caps |= MMC_CAP_1_8V_DDR; > > + /* > + * ROM code will change the bit burst_length_enable setting > + * to zero if this usdhc is choosed to boot system. Change > + * it back here, otherwise it will impact the performance a > + * lot. This bit is used to enable/disable the burst length > + * for the external AHB2AXI bridge, it's usefully especially > + * for INCR transfer because without burst length indicator, > + * the AHB2AXI bridge does not know the burst length in > + * advance. And without burst length indicator, AHB INCR > + * transfer can only be converted to singles on the AXI side. > + */ > + writel(readl(host->ioaddr + SDHCI_HOST_CONTROL) > + | ESDHC_BURST_LEN_EN_INCR, > + host->ioaddr + SDHCI_HOST_CONTROL); > + > if (!(imx_data->socdata->flags & ESDHC_FLAG_HS200)) > host->quirks2 |= SDHCI_QUIRK2_BROKEN_HS200; > > -- > 1.9.1 > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
