• Haibo Chen's avatar
    mmc: sdhci-esdhc-imx: clear the buffer_read_ready to reset standard tuning circuit · 9af372dc
    Haibo Chen authored
    To reset standard tuning circuit completely, after clear ESDHC_MIX_CTRL_EXE_TUNE,
    also need to clear bit buffer_read_ready, this operation will finally clear the
    USDHC IP internal logic flag execute_tuning_with_clr_buf, make sure the following
    normal data transfer will not be impacted by standard tuning logic used before.
    
    Find this issue when do quick SD card insert/remove stress test. During standard
    tuning prodedure, if remove SD card, USDHC standard tuning logic can't clear the
    internal flag execute_tuning_with_clr_buf. Next time when insert SD card, all
    data related commands can't get any data related interrupts, include data transfer
    complete interrupt, data timeout interrupt, data CRC interrupt, data end bit interrupt.
    Always trigger software timeout issue. Even reset the USDHC through bits in register
    SYS_CTRL (0x2C, bit28 reset tuning, bit26 reset data, bit 25 reset command, bit 24
    reset all) can't recover this. From the user's point of view, USDHC stuck, SD can't
    be recognized any more.
    
    Fixes: d9370424 ("mmc: sdhci-esdhc-imx: reset tuning circuit when power on mmc card")
    Signed-off-by: default avatarHaibo Chen <haibo.chen@nxp.com>
    Acked-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
    Cc: stable@vger.kernel.org
    Link: https://lore.kernel.org/r/1634263236-6111-1-git-send-email-haibo.chen@nxp.comSigned-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
    9af372dc
sdhci-esdhc-imx.c 57.2 KB