Mon, Mar 30, 2020 at 07:43:09AM +0000, ashiduka@xxxxxxxxxxx kirjoitti: > Dear Greg, Geert, > > > Right. > > Adding "#include <sys/ioctl.h>" to Greg's sample code causes a > > compilation error. > <snip> > > Is it normal to declare ioctl() without "#include <sys/ioctl.h>" ? > > I would be happy if you could give me some comments. > > > http://www.panix.com/~grante/arbitrary-baud.c > > We think this sample code is no good. > Should I work on glibc changes instead of kernel fixes? Side note: I hope introducing spd_cust hack hadn't made upstream. To the point. Use BOTHER as in code excerpt. Yes, there is a problematic parts with the headers regarding to this feature. But you may look how others solve it. https://github.com/npat-efault/picocom/blob/master/termios2.txt > > Subject: RE: [PATCH] serial: sh-sci: Support custom speed setting > > > > Dear Greg, Geert, > > > > > I guess you mean the forward declaration of ioctrl()? > > > No, they should include <sys/ioctl.h> instead. > > > > Right. > > Adding "#include <sys/ioctl.h>" to Greg's sample code causes a > > compilation error. > > > > > > I saw the code above, I thought I wouldn't write such code > > normally. > > > Why not? > > > > Is it normal to declare ioctl() without "#include <sys/ioctl.h>" ? > > > > Thanks & Best Regards, > > Yuusuke Ashiduka <ashiduka@xxxxxxxxxxx> > > Embedded System Development Dept. Embedded System Development Div. > > FUJITSU COMPUTER TECHNOLOGIES Ltd. > > > > > -----Original Message----- > > > From: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> > > > Sent: Thursday, March 12, 2020 6:03 PM > > > To: Torii, Kenichi/鳥居 健一 <torii.ken1@xxxxxxxxxxx> > > > Cc: gregkh@xxxxxxxxxxxxxxxxxxx; erosca@xxxxxxxxxxxxxx; > > > linux-serial@xxxxxxxxxxxxxxx; > > linux-renesas-soc@xxxxxxxxxxxxxxx; > > > wsa+renesas@xxxxxxxxxxxxxxxxxxxx; > > > yoshihiro.shimoda.uh@xxxxxxxxxxx; uli+renesas@xxxxxxxx; > > > george_davis@xxxxxxxxxx; andrew_gabbasov@xxxxxxxxxx; > > > jiada_wang@xxxxxxxxxx; yuichi.kusakabe@xxxxxxxxxxxxx; > > > yasano@xxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > > > jslaby@xxxxxxxx; yohhei.fukui@xxxxxxxxxxxxx; Ashizuka, Yuusuke/ > > > 芦塚 雄介 <ashiduka@xxxxxxxxxxx>; magnus.damm@xxxxxxxxx > > > Subject: Re: [PATCH] serial: sh-sci: Support custom speed setting > > > > > > Hi Torii-san, > > > > > > On Thu, Mar 12, 2020 at 6:10 AM torii.ken1@xxxxxxxxxxx > > > <torii.ken1@xxxxxxxxxxx> wrote: > > > > On Tue, 11 Feb 2020 05:57:35 +0900, > > > > Greg Kroah-Hartman wrote: > > > > > On Thu, Jan 30, 2020 at 01:32:50PM +0100, Geert Uytterhoeven > > > wrote: > > > > > > On Wed, Jan 29, 2020 at 5:20 PM Eugeniu Rosca > > > <erosca@xxxxxxxxxxxxxx> wrote: > > > > > > > From: Torii Kenichi <torii.ken1@xxxxxxxxxxxxxx> > > > > > > > > > > > > > > This patch is necessary to use BT module and XM module > > with > > > DENSO TEN > > > > > > > development board. > > > > > > > > > > > > > > This patch supports ASYNC_SPD_CUST flag by > > ioctl(TIOCSSERIAL), > > > enables > > > > > > > custom speed setting with setserial(1). > > > > > > > > > > > > > > The custom speed is calculated from uartclk and > > > custom_divisor. > > > > > > > If custom_divisor is zero, custom speed setting is invalid. > > > > > > > > > > > > > > Signed-off-by: Torii Kenichi <torii.ken1@xxxxxxxxxxxxxx> > > > > > > > [erosca: rebase against v5.5] > > > > > > > Signed-off-by: Eugeniu Rosca <erosca@xxxxxxxxxxxxxx> > > > > > > > > > > > > Thanks for your patch! > > > > > > > > > > > > While this seems to work fine[*], I have a few > > > comments/questions: > > > > > > 1. This feature seems to be deprecated: > > > > > > > > > > > > sh-sci e6e68000.serial: setserial sets custom speed > > > on > > > > > > ttySC1. This is deprecated. > > > > > > > > > > > > 2. As the wanted speed is specified as a divider, the > > resulting > > > speed > > > > > > may be off, cfr. the example for 57600 below. > > > > > > Note that the SCIF device has multiple clock inputs, > > and > > > can do > > > > > > 57600 perfectly if the right crystal has been fitted. > > > > > > > > > > > > 3. What to do with "[PATCH/RFC] serial: sh-sci: Update > > uartclk > > > based > > > > > > on selected clock" > > > (https://patchwork.kernel.org/patch/11103703/)? > > > > > > Combined with this, things become pretty complicated > > and > > > > > > unpredictable, as uartclk now always reflect the > > frequency > > > of the > > > > > > last used base clock, which was the optimal one for the > > > previously > > > > > > used speed.... > > > > > > > > > > > > I think it would be easier if we just had an API to specify > > > a raw speed. > > > > > > Perhaps that already exists? > > > > > > > > > > Yes, see: > > > > > http://www.panix.com/~grante/arbitrary-baud.c > > > > > > > > I saw the code above, I thought I wouldn't write such code > > normally. > > > > > > > > >#include <linux/termios.h> > > > > > > > > > >int ioctl(int d, int request, ...); > > > > > > > > Do application programmers have to accept this bad code? > > > > > > I guess you mean the forward declaration of ioctrl()? > > > No, they should include <sys/ioctl.h> instead. > > > > > > Gr{oetje,eeting}s, > > > > > > Geert > > > > > > -- > > > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- > > > geert@xxxxxxxxxxxxxx > > > > > > 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 -- With Best Regards, Andy Shevchenko
