> -----Original Message----- > From: Adrian Hunter [mailto:adrian.hunter@xxxxxxxxx] > Sent: 2020年8月6日 20:11 > To: Bough Chen <haibo.chen@xxxxxxx>; ulf.hansson@xxxxxxxxxx; > linux-mmc@xxxxxxxxxxxxxxx > Cc: dl-linux-imx <linux-imx@xxxxxxx>; shawnguo@xxxxxxxxxx; > s.hauer@xxxxxxxxxxxxxx; kernel@xxxxxxxxxxxxxx; festevam@xxxxxxxxx > Subject: Re: [PATCH] mmc: host: sdhci-esdhc-imx: reset usdhc before sending > tuning command for manual tuning method > > On 6/08/20 2:48 pm, haibo.chen@xxxxxxx wrote: > > From: Haibo Chen <haibo.chen@xxxxxxx> > > > > According to IC suggestion, everytime before sending the tuning > > command, need to reset the usdhc, so to reset the tuning circuit, to > > let every tuning command work well for the manual tuning method. For > > standard tuning method, IC already add the reset operation in the logic. > > > > Signed-off-by: Haibo Chen <haibo.chen@xxxxxxx> > > --- > > drivers/mmc/host/sdhci-esdhc-imx.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c > > b/drivers/mmc/host/sdhci-esdhc-imx.c > > index a76b4513fbec..e4694eb1b914 100644 > > --- a/drivers/mmc/host/sdhci-esdhc-imx.c > > +++ b/drivers/mmc/host/sdhci-esdhc-imx.c > > @@ -990,6 +990,7 @@ static void esdhc_prepare_tuning(struct sdhci_host > > *host, u32 val) > > > > /* FIXME: delay a bit for card to be ready for next tuning due to errors */ > > mdelay(1); > > + sdhci_reset(host, SDHCI_RESET_ALL); > > Doesn't that reset all registers i.e. the entire ios state? > Hi Adrian, For i.MX usdhc, RESET_ALL operation do not impact any register value, it just reset the internal logic setting. I already verified that. Here I just want to set the SDHCI_RESET_ALL bit, but I notice that the API sdhci_reset() will also touch the host->clock, so I'm not sure whether it is good enough to use this API directly. Any suggestion? At least, current patch can fix the manual tuning issue on imx7d/imx8qxp. > > > > reg = readl(host->ioaddr + ESDHC_MIX_CTRL); > > reg |= ESDHC_MIX_CTRL_EXE_TUNE | ESDHC_MIX_CTRL_SMPCLK_SEL | > >
