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authorMichał Mirosław <mirq-linux@rere.qmqm.pl>2020-01-15 10:54:35 +0100
committerUlf Hansson <ulf.hansson@linaro.org>2020-01-20 10:36:27 +0100
commit2a187d03352086e300daa2044051db00044cd171 (patch)
tree3d5f4c540dc15f5db24d3b2473c2b9a2f93cd30a /drivers/mmc
parentf571389c0b015e76f91c697c4c1700aba860d34f (diff)
mmc: sdhci: fix minimum clock rate for v3 controller
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.1579082031.git.mirq-linux@rere.qmqm.pl Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/host/sdhci.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 1b1c26da3fe0..659a9459ace3 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -3913,11 +3913,13 @@ int sdhci_setup_host(struct sdhci_host *host)
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;