On 13/07/18 16:39, Aapo Vienamo wrote: ... >>> that it returns the current clock rate of the host instead of the >>> maximum one, which can lead to unnecessarily small clock rates. >>> >>> This differs from the previous implementation of >>> tegra_sdhci_get_max_clock() in that it doesn't divide the result by two. >> >> Why? > > As far as I can tell the original tegra_sdhci_get_max_clock() was > implemented this way in order to force sdhci_calc_clk() to always set > the SDHCI clock divider to two on sdhci_set_clock(). The requirement to > configure the SDHCI divider to two is specific to DDR50/52 modes on > Tegra. > > The .get_max_clock() callback retuning half of the actual maximum will > result in HS200 and HS400 modes not being able to run at full speed. > Another mechanism to enforce the divider requirement has to be figured > out in order to enable DDR50/52 modes on Tegra SoCs. OK, thanks. Ah I see Stefan's patch for doubling the clock. OK so that's fine. Cheers Jon -- nvpublic -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
