From 78804de483c4d59d4e23acf8c9fb56eee07fb427 Mon Sep 17 00:00:00 2001 From: Yangbo Lu <yangbo.lu@nxp.com> Date: Tue, 1 Sep 2020 16:58:07 +0800 Subject: [PATCH] mmc: fsl_esdhc: fix eMMC HS400 stability issue There was a fix-up for eMMC HS400 stability issue in Linux. Patch link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ commit/?id=58d0bf843b49fa99588ac9f85178bd8dfd651b53 Description: Currently only LX2160A eSDHC supports eMMC HS400. According to a large number of tests, eMMC HS400 failed to work at 150MHz, and for a few boards failed to work at 175MHz. But eMMC HS400 worked fine on 200MHz. We hadn't found the root cause but setting eSDHC_DLLCFG0[DLL_FREQ_SEL] = 0 using slow delay chain seemed to resovle this issue. Let's use this as fixup for now. Introduce the fix-up in u-boot since the issue could be reproduced in u-boot too. Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> --- drivers/mmc/fsl_esdhc.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c index ce87416f5d..a6092ad26f 100644 --- a/drivers/mmc/fsl_esdhc.c +++ b/drivers/mmc/fsl_esdhc.c @@ -644,7 +644,10 @@ static void esdhc_set_timing(struct fsl_esdhc_priv *priv, enum bus_mode mode) esdhc_setbits32(®s->sdclkctl, CMD_CLK_CTL); esdhc_clock_control(priv, true); - esdhc_setbits32(®s->dllcfg0, DLL_ENABLE | DLL_FREQ_SEL); + if (priv->clock == 200000000) + esdhc_setbits32(®s->dllcfg0, DLL_FREQ_SEL); + + esdhc_setbits32(®s->dllcfg0, DLL_ENABLE); esdhc_setbits32(®s->tbctl, HS400_WNDW_ADJUST); esdhc_clock_control(priv, false); -- 2.39.5