From b6f44082d5cd2ea2758f09df4e364ded6f81323a Mon Sep 17 00:00:00 2001 From: T Karthik Reddy Date: Mon, 2 Aug 2021 23:20:45 -0600 Subject: [PATCH] mmc: zynq_sdhci: Wait till sd card detect state is stable As per SD spec when SD host controller is reset, it takes 1000msec to detect the card state. In case, if we enable the sd bus voltage & card detect state is not stable, then host controller will disable the sd bus voltage. In case of warm/subsystem reboot, due to unstable card detect state host controller is disabling the sd bus voltage to sd card causing sd card timeout error. So we wait for a maximum of 1000msec to get the card detect state stable before we enable the sd bus voltage. This current fix is workaround for now, this needs to be analysed further. Zynqmp platform should behave the same as Versal, but we did not encounter this issue as of now. So we are fixing it for Versal only. Signed-off-by: T Karthik Reddy Signed-off-by: Ashok Reddy Soma Reviewed-by: Jaehoon Chung Signed-off-by: Michal Simek --- drivers/mmc/zynq_sdhci.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/drivers/mmc/zynq_sdhci.c b/drivers/mmc/zynq_sdhci.c index 9a1693940a..4a877b4ce8 100644 --- a/drivers/mmc/zynq_sdhci.c +++ b/drivers/mmc/zynq_sdhci.c @@ -776,6 +776,25 @@ static int arasan_sdhci_probe(struct udevice *dev) return ret; upriv->mmc = host->mmc; + /* + * WORKAROUND: Versal platforms have an issue with card detect state. + * Due to this, host controller is switching off voltage to sd card + * causing sd card timeout error. Workaround this by adding a wait for + * 1000msec till the card detect state gets stable. + */ + if (IS_ENABLED(CONFIG_ARCH_VERSAL)) { + u32 timeout = 1000; + + while (((sdhci_readl(host, SDHCI_PRESENT_STATE) & + SDHCI_CARD_STATE_STABLE) == 0) && timeout--) { + mdelay(1); + } + if (!timeout) { + dev_err(dev, "Sdhci card detect state not stable\n"); + return -ETIMEDOUT; + } + } + return sdhci_probe(dev); } -- 2.39.5