Hello Heiner, W dniu 16.02.2017 o 20:42, Heiner Kallweit pisze: > This clk_disable_unprepare isn't right here. At first the condition > should be "if (ret)" as the disable/unprepare is supposed to be > executed if the previous command fails. > And if the previous command fails and meson_mmc_clk_init returns > an error, then probe jumps to label free_host where we have this > disable/unprepare already. > > Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx> > --- > v2: > - extended commit message > --- > drivers/mmc/host/meson-gx-mmc.c | 6 +----- > 1 file changed, 1 insertion(+), 5 deletions(-) > > diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c > index 68e76fa8..850b0152 100644 > --- a/drivers/mmc/host/meson-gx-mmc.c > +++ b/drivers/mmc/host/meson-gx-mmc.c > @@ -320,11 +320,7 @@ static int meson_mmc_clk_init(struct meson_host *host) > /* Get the nearest minimum clock to 400KHz */ > host->mmc->f_min = clk_round_rate(host->cfg_div_clk, 400000); > > - ret = meson_mmc_clk_set(host, host->mmc->f_min); > - if (!ret) > - clk_disable_unprepare(host->cfg_div_clk); > - > - return ret; > + return meson_mmc_clk_set(host, host->mmc->f_min); > } > > static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) > I see one problem here. As you said, if the previous command (that is the meson_mmc_clk_set function call) fails, then the whole meson_mmc_clk_init returns an error value, and meson_mmc_probe jumps to free_host and disables the clock there. But what happens if the clk_prepare_enable is the line that fails? in this case, the function returns an error value too, and in the free_host meson_mmc_probe tries to disable the clock that is not enabled, and that probably results in a kernel warning because you tried to disable a disabled clock. I was preparing a patch to disable clocks in the probe function only if they were enabled before, but then the meson_mmc_clk_init function remains a problem, because we don't know if the clock was enabled successfully or not when it returns an error.
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