| Message ID | 1447958344-836-9-git-send-email-geert+renesas@glider.be (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Geert Uytterhoeven |
| Headers | show |
Hi Geert, Thank you for the patch. On Thursday 19 November 2015 19:38:47 Geert Uytterhoeven wrote: > Move the -1 offset of br to the assignment to *brr, so br cannot become > negative anymore, and update the clamp() call. Now all unsigned values > in sci_baud_calc_hscif() can become unsigned. > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> > --- > drivers/tty/serial/sh-sci.c | 11 ++++++----- > 1 file changed, 6 insertions(+), 5 deletions(-) > > diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c > index 9442961a198378c7..fba1e1eea15dc3a1 100644 > --- a/drivers/tty/serial/sh-sci.c > +++ b/drivers/tty/serial/sh-sci.c > @@ -1870,7 +1870,8 @@ static unsigned int sci_scbrr_calc(struct sci_port *s, > unsigned int bps, static void sci_baud_calc_hscif(unsigned int bps, > unsigned long freq, int *brr, unsigned int *srr, unsigned int *cks) > { > - int sr, c, br, err, recv_margin; > + unsigned int sr, br, c; > + int err, recv_margin; > int min_err = 1000; /* 100% */ > int recv_max_margin = 0; > > @@ -1880,9 +1881,9 @@ static void sci_baud_calc_hscif(unsigned int bps, > unsigned long freq, int *brr, for (c = 0; c <= 3; c++) { > /* integerized formulas from HSCIF documentation */ > br = DIV_ROUND_CLOSEST(freq, (sr * > - (1 << (2 * c + 1)) * bps)) - 1; > - br = clamp(br, 0, 255); > - err = DIV_ROUND_CLOSEST(freq, ((br + 1) * bps * sr * > + (1 << (2 * c + 1)) * bps)); > + br = clamp(br, 1U, 256U); > + err = DIV_ROUND_CLOSEST(freq, (br * bps * sr * > (1 << (2 * c + 1)) / 1000)) - > 1000; While you're at it you can remove the parentheses around the second argument to DIV_ROUND_CLOSEST, they're not needed. > /* Calc recv margin > @@ -1908,7 +1909,7 @@ static void sci_baud_calc_hscif(unsigned int bps, > unsigned long freq, int *brr, else > continue; > > - *brr = br; > + *brr = br - 1; > *srr = sr - 1; > *cks = c; > }
On Thu, Nov 19, 2015 at 9:36 PM, Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote: >> --- a/drivers/tty/serial/sh-sci.c >> +++ b/drivers/tty/serial/sh-sci.c >> @@ -1880,9 +1881,9 @@ static void sci_baud_calc_hscif(unsigned int bps, >> unsigned long freq, int *brr, for (c = 0; c <= 3; c++) { >> /* integerized formulas from HSCIF documentation */ >> br = DIV_ROUND_CLOSEST(freq, (sr * >> - (1 << (2 * c + 1)) * bps)) - 1; >> - br = clamp(br, 0, 255); >> - err = DIV_ROUND_CLOSEST(freq, ((br + 1) * bps * sr * >> + (1 << (2 * c + 1)) * bps)); >> + br = clamp(br, 1U, 256U); >> + err = DIV_ROUND_CLOSEST(freq, (br * bps * sr * >> (1 << (2 * c + 1)) / 1000)) - >> 1000; > > While you're at it you can remove the parentheses around the second argument > to DIV_ROUND_CLOSEST, they're not needed. The factor between parentheses is removed in the next patch. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-sh" 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/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 9442961a198378c7..fba1e1eea15dc3a1 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1870,7 +1870,8 @@ static unsigned int sci_scbrr_calc(struct sci_port *s, unsigned int bps, static void sci_baud_calc_hscif(unsigned int bps, unsigned long freq, int *brr, unsigned int *srr, unsigned int *cks) { - int sr, c, br, err, recv_margin; + unsigned int sr, br, c; + int err, recv_margin; int min_err = 1000; /* 100% */ int recv_max_margin = 0; @@ -1880,9 +1881,9 @@ static void sci_baud_calc_hscif(unsigned int bps, unsigned long freq, int *brr, for (c = 0; c <= 3; c++) { /* integerized formulas from HSCIF documentation */ br = DIV_ROUND_CLOSEST(freq, (sr * - (1 << (2 * c + 1)) * bps)) - 1; - br = clamp(br, 0, 255); - err = DIV_ROUND_CLOSEST(freq, ((br + 1) * bps * sr * + (1 << (2 * c + 1)) * bps)); + br = clamp(br, 1U, 256U); + err = DIV_ROUND_CLOSEST(freq, (br * bps * sr * (1 << (2 * c + 1)) / 1000)) - 1000; /* Calc recv margin @@ -1908,7 +1909,7 @@ static void sci_baud_calc_hscif(unsigned int bps, unsigned long freq, int *brr, else continue; - *brr = br; + *brr = br - 1; *srr = sr - 1; *cks = c; }
Move the -1 offset of br to the assignment to *brr, so br cannot become negative anymore, and update the clamp() call. Now all unsigned values in sci_baud_calc_hscif() can become unsigned. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> --- drivers/tty/serial/sh-sci.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)