From: Alex Leibovich alexl@marvell.com
commit 1a3ed0dc3594d99ff341ec63865a40519ea24b8d upstream.
Automatic Clock Gating is a feature used for the power consumption optimisation. It turned out that during early init phase it may prevent the stable voltage switch to 1.8V - due to that on some platforms an endless printout in dmesg can be observed: "mmc1: 1.8V regulator output did not became stable" Fix the problem by disabling the ACG at very beginning of the sdhci_init and let that be enabled later.
Fixes: 3a3748dba881 ("mmc: sdhci-xenon: Add Marvell Xenon SDHC core functionality") Signed-off-by: Alex Leibovich alexl@marvell.com Signed-off-by: Marcin Wojtas mw@semihalf.com Cc: stable@vger.kernel.org Acked-by: Adrian Hunter adrian.hunter@intel.com Link: https://lore.kernel.org/r/20201211141656.24915-1-mw@semihalf.com Signed-off-by: Ulf Hansson ulf.hansson@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/mmc/host/sdhci-xenon.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
--- a/drivers/mmc/host/sdhci-xenon.c +++ b/drivers/mmc/host/sdhci-xenon.c @@ -170,7 +170,12 @@ static void xenon_reset_exit(struct sdhc /* Disable tuning request and auto-retuning again */ xenon_retune_setup(host);
- xenon_set_acg(host, true); + /* + * The ACG should be turned off at the early init time, in order + * to solve a possible issues with the 1.8V regulator stabilization. + * The feature is enabled in later stage. + */ + xenon_set_acg(host, false);
xenon_set_sdclk_off_idle(host, sdhc_id, false);