From: Michał Mirosław mirq-linux@rere.qmqm.pl
commit 2a187d03352086e300daa2044051db00044cd171 upstream.
For SDHCIv3+ with programmable clock mode, minimal clock frequency is still base clock / max(divider). Minimal programmable clock frequency is always greater than minimal divided clock frequency. Without this patch, SDHCI uses out-of-spec initial frequency when multiplier is big enough:
mmc1: mmc_rescan_try_freq: trying to init card at 468750 Hz [for 480 MHz source clock divided by 1024]
The code in sdhci_calc_clk() already chooses a correct SDCLK clock mode.
Fixes: c3ed3877625f ("mmc: sdhci: add support for programmable clock mode") Cc: stable@vger.kernel.org # 4f6aa3264af4: mmc: tegra: Only advertise UHS modes if IO regulator is present Cc: stable@vger.kernel.org Signed-off-by: Michał Mirosław mirq-linux@rere.qmqm.pl Acked-by: Adrian Hunter adrian.hunter@intel.com Link: https://lore.kernel.org/r/ffb489519a446caffe7a0a05c4b9372bd52397bb.157908203... Signed-off-by: Ulf Hansson ulf.hansson@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/mmc/host/sdhci.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
--- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -3096,11 +3096,13 @@ int sdhci_add_host(struct sdhci_host *ho if (host->ops->get_min_clock) mmc->f_min = host->ops->get_min_clock(host); else if (host->version >= SDHCI_SPEC_300) { - if (host->clk_mul) { - mmc->f_min = (host->max_clk * host->clk_mul) / 1024; + if (host->clk_mul) max_clk = host->max_clk * host->clk_mul; - } else - mmc->f_min = host->max_clk / SDHCI_MAX_DIV_SPEC_300; + /* + * Divided Clock Mode minimum clock rate is always less than + * Programmable Clock Mode minimum clock rate. + */ + mmc->f_min = host->max_clk / SDHCI_MAX_DIV_SPEC_300; } else mmc->f_min = host->max_clk / SDHCI_MAX_DIV_SPEC_200;