From: Faiz Abbas faiz_abbas@ti.com
[ Upstream commit feb40824d78eac5e48f56498dca941754dff33d7 ]
According to the App note[1] detailing the tuning algorithm, for temperatures < -20C, the initial tuning value should be min(largest value in LPW - 24, ceil(13/16 ratio of LPW)). The largest value in LPW is (max_window + 4 * (max_len - 1)) and not (max_window + 4 * max_len) itself. Fix this implementation.
[1] http://www.ti.com/lit/an/spraca9b/spraca9b.pdf
Fixes: 961de0a856e3 ("mmc: sdhci-omap: Workaround errata regarding SDR104/HS200 tuning failures (i929)") Cc: stable@vger.kernel.org Signed-off-by: Faiz Abbas faiz_abbas@ti.com Signed-off-by: Ulf Hansson ulf.hansson@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/mmc/host/sdhci-omap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/mmc/host/sdhci-omap.c b/drivers/mmc/host/sdhci-omap.c index 833e13cabd2a8..05ade7a2dd243 100644 --- a/drivers/mmc/host/sdhci-omap.c +++ b/drivers/mmc/host/sdhci-omap.c @@ -387,7 +387,7 @@ static int sdhci_omap_execute_tuning(struct mmc_host *mmc, u32 opcode) * on temperature */ if (temperature < -20000) - phase_delay = min(max_window + 4 * max_len - 24, + phase_delay = min(max_window + 4 * (max_len - 1) - 24, max_window + DIV_ROUND_UP(13 * max_len, 16) * 4); else if (temperature < 20000)