| Message ID | 1415179995-25062-2-git-send-email-boris.brezillon@free-electrons.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hello! Just confirming this exact patch fixes the problem I was running into. On Wed, Nov 05, 2014 at 10:33:14AM +0100, Boris Brezillon wrote: > at91rm9200_clk_usb_set_rate might fail depending on the requested rate, > because the parent_rate / rate remainder is not necessarily zero. > Moreover, when rounding down the calculated rate we might alter the > divisor calculation and end up with an invalid divisor. > > To solve those problems, accept a non zero remainder, and always round > division to the closest result. > > Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> > Reported-by: Andreas Henriksson <andreas.henriksson@endian.se> Tested-by: Andreas Henriksson <andreas.henriksson@endian.se> > --- > drivers/clk/at91/clk-usb.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/clk/at91/clk-usb.c b/drivers/clk/at91/clk-usb.c > index 24b5b02..5b3b63c 100644 > --- a/drivers/clk/at91/clk-usb.c > +++ b/drivers/clk/at91/clk-usb.c > @@ -253,7 +253,7 @@ static long at91rm9200_clk_usb_round_rate(struct clk_hw *hw, unsigned long rate, > > tmp_parent_rate = rate * usb->divisors[i]; > tmp_parent_rate = __clk_round_rate(parent, tmp_parent_rate); > - tmprate = tmp_parent_rate / usb->divisors[i]; > + tmprate = DIV_ROUND_CLOSEST(tmp_parent_rate, usb->divisors[i]); > if (tmprate < rate) > tmpdiff = rate - tmprate; > else > @@ -281,10 +281,10 @@ static int at91rm9200_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate, > struct at91_pmc *pmc = usb->pmc; > unsigned long div; > > - if (!rate || parent_rate % rate) > + if (!rate) > return -EINVAL; > > - div = parent_rate / rate; > + div = DIV_ROUND_CLOSEST(parent_rate, rate); > > for (i = 0; i < RM9200_USB_DIV_TAB_SIZE; i++) { > if (usb->divisors[i] == div) { > -- > 1.9.1 >
diff --git a/drivers/clk/at91/clk-usb.c b/drivers/clk/at91/clk-usb.c index 24b5b02..5b3b63c 100644 --- a/drivers/clk/at91/clk-usb.c +++ b/drivers/clk/at91/clk-usb.c @@ -253,7 +253,7 @@ static long at91rm9200_clk_usb_round_rate(struct clk_hw *hw, unsigned long rate, tmp_parent_rate = rate * usb->divisors[i]; tmp_parent_rate = __clk_round_rate(parent, tmp_parent_rate); - tmprate = tmp_parent_rate / usb->divisors[i]; + tmprate = DIV_ROUND_CLOSEST(tmp_parent_rate, usb->divisors[i]); if (tmprate < rate) tmpdiff = rate - tmprate; else @@ -281,10 +281,10 @@ static int at91rm9200_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate, struct at91_pmc *pmc = usb->pmc; unsigned long div; - if (!rate || parent_rate % rate) + if (!rate) return -EINVAL; - div = parent_rate / rate; + div = DIV_ROUND_CLOSEST(parent_rate, rate); for (i = 0; i < RM9200_USB_DIV_TAB_SIZE; i++) { if (usb->divisors[i] == div) {
at91rm9200_clk_usb_set_rate might fail depending on the requested rate, because the parent_rate / rate remainder is not necessarily zero. Moreover, when rounding down the calculated rate we might alter the divisor calculation and end up with an invalid divisor. To solve those problems, accept a non zero remainder, and always round division to the closest result. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Reported-by: Andreas Henriksson <andreas.henriksson@endian.se> --- drivers/clk/at91/clk-usb.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)