| Message ID | 476265c8-b7e8-acdb-1964-5663c629caa3@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 02/01/2017 05:57 AM, Heiner Kallweit wrote: > Currently f_min is set to 4 MHz whilst the comment states 400 MHz. > I think the itention is to set f_min to 400 kHz. > Change value and comment accordingly. > > Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> > --- > drivers/mmc/host/meson-gx-mmc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c > index 5eca88bc..da3cce31 100644 > --- a/drivers/mmc/host/meson-gx-mmc.c > +++ b/drivers/mmc/host/meson-gx-mmc.c > @@ -268,7 +268,7 @@ static int meson_mmc_clk_init(struct meson_host *host) > if (f_min != UINT_MAX) > f_min = DIV_ROUND_UP(CLK_SRC_XTAL_RATE, CLK_DIV_MAX); > else > - f_min = 4000000; /* default min: 400 MHz */ > + f_min = 400000; /* default min: 400 kHz */ I'm not sure but f_min can be 100KHz by default, not 400KHz. Because mmc-core should be try to find frequency from 400KHz to "f_min" value. Best Regards, Jaehoon Chung > host->mmc->f_min = f_min; > > /* create the mux */ > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Am 01.02.2017 um 12:49 schrieb Jaehoon Chung: > On 02/01/2017 05:57 AM, Heiner Kallweit wrote: >> Currently f_min is set to 4 MHz whilst the comment states 400 MHz. >> I think the itention is to set f_min to 400 kHz. >> Change value and comment accordingly. >> >> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> >> --- >> drivers/mmc/host/meson-gx-mmc.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c >> index 5eca88bc..da3cce31 100644 >> --- a/drivers/mmc/host/meson-gx-mmc.c >> +++ b/drivers/mmc/host/meson-gx-mmc.c >> @@ -268,7 +268,7 @@ static int meson_mmc_clk_init(struct meson_host *host) >> if (f_min != UINT_MAX) >> f_min = DIV_ROUND_UP(CLK_SRC_XTAL_RATE, CLK_DIV_MAX); >> else >> - f_min = 4000000; /* default min: 400 MHz */ >> + f_min = 400000; /* default min: 400 kHz */ > > I'm not sure but f_min can be 100KHz by default, not 400KHz. > Because mmc-core should be try to find frequency from 400KHz to "f_min" value. > Actually I wonder how we can ever reach this part of the if clause. If at least one parent clock is defined and we can get its clock rate then f_min != UINT_MAX. Can we think of a case where no parent clock is defined? And would it make sense at all to proceed in this case? > Best Regards, > Jaehoon Chung > >> host->mmc->f_min = f_min; >> >> /* create the mux */ >> > > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Heiner Kallweit <hkallweit1@gmail.com> writes: > Am 01.02.2017 um 12:49 schrieb Jaehoon Chung: >> On 02/01/2017 05:57 AM, Heiner Kallweit wrote: >>> Currently f_min is set to 4 MHz whilst the comment states 400 MHz. >>> I think the itention is to set f_min to 400 kHz. >>> Change value and comment accordingly. >>> >>> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> >>> --- >>> drivers/mmc/host/meson-gx-mmc.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c >>> index 5eca88bc..da3cce31 100644 >>> --- a/drivers/mmc/host/meson-gx-mmc.c >>> +++ b/drivers/mmc/host/meson-gx-mmc.c >>> @@ -268,7 +268,7 @@ static int meson_mmc_clk_init(struct meson_host *host) >>> if (f_min != UINT_MAX) >>> f_min = DIV_ROUND_UP(CLK_SRC_XTAL_RATE, CLK_DIV_MAX); >>> else >>> - f_min = 4000000; /* default min: 400 MHz */ >>> + f_min = 400000; /* default min: 400 kHz */ >> >> I'm not sure but f_min can be 100KHz by default, not 400KHz. >> Because mmc-core should be try to find frequency from 400KHz to "f_min" value. >> > Actually I wonder how we can ever reach this part of the if clause. > If at least one parent clock is defined and we can get its clock rate > then f_min != UINT_MAX. > Can we think of a case where no parent clock is defined? > And would it make sense at all to proceed in this case? This is actually common while adding a new board or SoC and is a useful fallback/safeguard. Kevin -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c index 5eca88bc..da3cce31 100644 --- a/drivers/mmc/host/meson-gx-mmc.c +++ b/drivers/mmc/host/meson-gx-mmc.c @@ -268,7 +268,7 @@ static int meson_mmc_clk_init(struct meson_host *host) if (f_min != UINT_MAX) f_min = DIV_ROUND_UP(CLK_SRC_XTAL_RATE, CLK_DIV_MAX); else - f_min = 4000000; /* default min: 400 MHz */ + f_min = 400000; /* default min: 400 kHz */ host->mmc->f_min = f_min; /* create the mux */
Currently f_min is set to 4 MHz whilst the comment states 400 MHz. I think the itention is to set f_min to 400 kHz. Change value and comment accordingly. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> --- drivers/mmc/host/meson-gx-mmc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)