diff options
| author | Michał Mirosław <mirq-linux@rere.qmqm.pl> | 2020-01-15 10:54:35 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-01-29 10:21:51 +0100 |
| commit | 131df943a46880f4e9a512a25bc0da55164165e1 (patch) | |
| tree | 4832819c3b245f3a44996003a4dfa3875b0c1a43 /drivers/mmc/host/sdhci.c | |
| parent | f2b7596f90124f60e36ffb8bea4f93061f5e94f4 (diff) | |
mmc: sdhci: fix minimum clock rate for v3 controller
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.1579082031.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/mmc/host/sdhci.c')
| -rw-r--r-- | drivers/mmc/host/sdhci.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 2bae0214528b..bf309a8a66a1 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -3096,11 +3096,13 @@ int sdhci_add_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; |