22.04.2022 20:09, Sebastian Reichel пишет: > From: Yifeng Zhao <yifeng.zhao@xxxxxxxxxxxxxx> > > The reset function build in the SDHCI will not reset the logic > circuit related to the tuning function, which may cause data > reading errors. Resetting the complete SDHCI controller through > the reset controller fixes the issue. > > Signed-off-by: Yifeng Zhao <yifeng.zhao@xxxxxxxxxxxxxx> > [rebase] > Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx> > --- > drivers/mmc/host/sdhci-of-dwcmshc.c | 28 +++++++++++++++++++++++++++- > 1 file changed, 27 insertions(+), 1 deletion(-) > > diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c > index bac874ab0b33..d95ae6ca1256 100644 > --- a/drivers/mmc/host/sdhci-of-dwcmshc.c > +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c > @@ -15,6 +15,7 @@ > #include <linux/module.h> > #include <linux/of.h> > #include <linux/of_device.h> > +#include <linux/reset.h> > #include <linux/sizes.h> > > #include "sdhci-pltfm.h" > @@ -63,6 +64,7 @@ > struct rk3568_priv { > /* Rockchip specified optional clocks */ > struct clk_bulk_data rockchip_clks[RK3568_MAX_CLKS]; > + struct reset_control *reset; > u8 txclk_tapnum; > }; > > @@ -255,6 +257,23 @@ static void dwcmshc_rk3568_set_clock(struct sdhci_host *host, unsigned int clock > sdhci_writel(host, extra, DWCMSHC_EMMC_DLL_STRBIN); > } > > +static void rk35xx_sdhci_reset(struct sdhci_host *host, u8 mask) > +{ > + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); > + struct dwcmshc_priv *dwc_priv = sdhci_pltfm_priv(pltfm_host); > + struct rk35xx_priv *priv = dwc_priv->priv; > + > + if (mask & SDHCI_RESET_ALL) { > + if (!IS_ERR_OR_NULL(priv->reset)) { priv->reset can't be a error ptr since probe fails on error. > + reset_control_assert(priv->reset); > + udelay(1); > + reset_control_deassert(priv->reset); > + } > + } > + > + sdhci_reset(host, mask); > +} > + > static const struct sdhci_ops sdhci_dwcmshc_ops = { > .set_clock = sdhci_set_clock, > .set_bus_width = sdhci_set_bus_width, > @@ -269,7 +288,7 @@ static const struct sdhci_ops sdhci_dwcmshc_rk3568_ops = { > .set_bus_width = sdhci_set_bus_width, > .set_uhs_signaling = dwcmshc_set_uhs_signaling, > .get_max_clock = sdhci_pltfm_clk_get_max_clock, > - .reset = sdhci_reset, > + .reset = rk35xx_sdhci_reset, > .adma_write_desc = dwcmshc_adma_write_desc, > }; > > @@ -292,6 +311,13 @@ static int dwcmshc_rk3568_init(struct sdhci_host *host, struct dwcmshc_priv *dwc > int err; > struct rk3568_priv *priv = dwc_priv->priv; > > + priv->reset = devm_reset_control_array_get_exclusive(mmc_dev(host->mmc)); The devm_reset_control_array_get_exclusive() never returns NULL. The devm_reset_control_array_get_optional_exclusive(() may return NULL if reset is missing in DT, perhaps that's what you actually want? > + if (IS_ERR_OR_NULL(priv->reset)) { > + err = PTR_ERR(priv->reset); NULL isn't a error > + dev_err(mmc_dev(host->mmc), "failed to get reset control %d\n", err); dev_err_probe()?