| Message ID | 20180806140755.24087-4-geert+renesas@glider.be (mailing list archive) |
|---|---|
| State | RFC |
| Delegated to: | Geert Uytterhoeven |
| Headers | show |
| Series | sh-sci : Do not derive regshift from regsize | expand |
Hi Geert, Thank you for the patch. On Monday, 6 August 2018 17:07:54 EEST Geert Uytterhoeven wrote: > This reverts commit dfc80387aefb78161f83732804c6d01c89c24595. > > Deriving the proper regshift value from the register block size is > fragile, as it may have been rounded up. > > Furthermore we will need plat_sci_port.regshift again. Won't this break bisection ? Shouldn't you squash patches 3 and 4 together ? Does this mechanism break anything on non-DT platforms ? If not I'd rather keep it for them, and only use compat strings for DT platforms, to avoiding adding back a platform data field. > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> > --- > arch/sh/kernel/cpu/sh3/setup-sh770x.c | 1 + > arch/sh/kernel/cpu/sh4/setup-sh7750.c | 3 ++- > arch/sh/kernel/cpu/sh4/setup-sh7760.c | 10 ++-------- > drivers/tty/serial/sh-sci.c | 8 +------- > include/linux/serial_sci.h | 1 + > 5 files changed, 7 insertions(+), 16 deletions(-) > > diff --git a/arch/sh/kernel/cpu/sh3/setup-sh770x.c > b/arch/sh/kernel/cpu/sh3/setup-sh770x.c index > 59a88611df55ac8f..592cd9ab30c4272f 100644 > --- a/arch/sh/kernel/cpu/sh3/setup-sh770x.c > +++ b/arch/sh/kernel/cpu/sh3/setup-sh770x.c > @@ -111,6 +111,7 @@ static struct platform_device rtc_device = { > static struct plat_sci_port scif0_platform_data = { > .type = PORT_SCI, > .ops = &sh770x_sci_port_ops, > + .regshift = 1, > }; > > static struct resource scif0_resources[] = { > diff --git a/arch/sh/kernel/cpu/sh4/setup-sh7750.c > b/arch/sh/kernel/cpu/sh4/setup-sh7750.c index > 57d30689204d03b9..d98a55416306baef 100644 > --- a/arch/sh/kernel/cpu/sh4/setup-sh7750.c > +++ b/arch/sh/kernel/cpu/sh4/setup-sh7750.c > @@ -39,10 +39,11 @@ static struct platform_device rtc_device = { > > static struct plat_sci_port sci_platform_data = { > .type = PORT_SCI, > + .regshift = 2, > }; > > static struct resource sci_resources[] = { > - DEFINE_RES_MEM(0xffe00000, 0x20), > + DEFINE_RES_MEM(0xffe00000, 0x100), > DEFINE_RES_IRQ(evt2irq(0x4e0)), > }; > > diff --git a/arch/sh/kernel/cpu/sh4/setup-sh7760.c > b/arch/sh/kernel/cpu/sh4/setup-sh7760.c index > e51fe1734e1368e8..0c0cdfc69dcc3e33 100644 > --- a/arch/sh/kernel/cpu/sh4/setup-sh7760.c > +++ b/arch/sh/kernel/cpu/sh4/setup-sh7760.c > @@ -200,18 +200,12 @@ static struct platform_device scif2_device = { > }; > > static struct plat_sci_port scif3_platform_data = { > - /* > - * This is actually a SIM card module serial port, based on an SCI with > - * additional registers. The sh-sci driver doesn't support the SIM port > - * type, declare it as a SCI. Don't declare the additional registers in > - * the memory resource or the driver will compute an incorrect regshift > - * value. > - */ > .type = PORT_SCI, > + .regshift = 2, > }; > > static struct resource scif3_resources[] = { > - DEFINE_RES_MEM(0xfe480000, 0x10), > + DEFINE_RES_MEM(0xfe480000, 0x100), > DEFINE_RES_IRQ(evt2irq(0xc00)), > DEFINE_RES_IRQ(evt2irq(0xc20)), > DEFINE_RES_IRQ(evt2irq(0xc40)), > diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c > index caf4422d9e2e59e4..955c057dff6e8c78 100644 > --- a/drivers/tty/serial/sh-sci.c > +++ b/drivers/tty/serial/sh-sci.c > @@ -2895,15 +2895,9 @@ static int sci_init_single(struct platform_device > *dev, > > port->type = p->type; > port->flags = UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags; > + port->regshift = p->regshift; > port->fifosize = sci_port->params->fifosize; > > - if (port->type == PORT_SCI) { > - if (sci_port->reg_size >= 0x20) > - port->regshift = 2; > - else > - port->regshift = 1; > - } > - > if (regtype == SCIx_SH4_SCIF_REGTYPE) > if (sci_port->reg_size >= 0x20) > port->regshift = 1; > diff --git a/include/linux/serial_sci.h b/include/linux/serial_sci.h > index c0e795d95477daea..eebb12fc473f49a2 100644 > --- a/include/linux/serial_sci.h > +++ b/include/linux/serial_sci.h > @@ -57,6 +57,7 @@ struct plat_sci_port { > /* > * Platform overrides if necessary, defaults otherwise. > */ > + unsigned char regshift; > unsigned char regtype; > > struct plat_sci_port_ops *ops;
Hi Laurent, On Mon, Aug 6, 2018 at 4:16 PM Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote: > On Monday, 6 August 2018 17:07:54 EEST Geert Uytterhoeven wrote: > > This reverts commit dfc80387aefb78161f83732804c6d01c89c24595. > > > > Deriving the proper regshift value from the register block size is > > fragile, as it may have been rounded up. > > > > Furthermore we will need plat_sci_port.regshift again. > > Won't this break bisection ? Shouldn't you squash patches 3 and 4 together ? > > Does this mechanism break anything on non-DT platforms ? If not I'd rather > keep it for them, and only use compat strings for DT platforms, to avoiding > adding back a platform data field. Actually I think the original commit broke SCI on H8/300, as regshift should be zero on that platform. But that was not discovered until recently. Gr{oetje,eeting}s, Geert
Hi Geert, On Monday, 6 August 2018 17:34:34 EEST Geert Uytterhoeven wrote: > On Mon, Aug 6, 2018 at 4:16 PM Laurent Pinchart wrote: > > On Monday, 6 August 2018 17:07:54 EEST Geert Uytterhoeven wrote: > >> This reverts commit dfc80387aefb78161f83732804c6d01c89c24595. > >> > >> Deriving the proper regshift value from the register block size is > >> fragile, as it may have been rounded up. > >> > >> Furthermore we will need plat_sci_port.regshift again. > > > > Won't this break bisection ? Shouldn't you squash patches 3 and 4 together > > ? > > > > Does this mechanism break anything on non-DT platforms ? If not I'd rather > > keep it for them, and only use compat strings for DT platforms, to > > avoiding adding back a platform data field. > > Actually I think the original commit broke SCI on H8/300, as regshift should > be zero on that platform. > But that was not discovered until recently. So there are still people booting H3/800 ? :-) Could we still keep the mechanism for SH and fix H8/300 with special handling somewhere ?
Hi Laurent, On Mon, Aug 6, 2018 at 4:40 PM Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote: > On Monday, 6 August 2018 17:34:34 EEST Geert Uytterhoeven wrote: > > On Mon, Aug 6, 2018 at 4:16 PM Laurent Pinchart wrote: > > > On Monday, 6 August 2018 17:07:54 EEST Geert Uytterhoeven wrote: > > >> This reverts commit dfc80387aefb78161f83732804c6d01c89c24595. > > >> > > >> Deriving the proper regshift value from the register block size is > > >> fragile, as it may have been rounded up. > > >> > > >> Furthermore we will need plat_sci_port.regshift again. > > > > > > Won't this break bisection ? Shouldn't you squash patches 3 and 4 together > > > ? > > > > > > Does this mechanism break anything on non-DT platforms ? If not I'd rather > > > keep it for them, and only use compat strings for DT platforms, to > > > avoiding adding back a platform data field. > > > > Actually I think the original commit broke SCI on H8/300, as regshift should > > be zero on that platform. > > But that was not discovered until recently. > > So there are still people booting H3/800 ? :-) Yes, remember, H8/300 was resurrected with full DT support. SuperH is the legacy one ;-) > Could we still keep the mechanism for SH and fix H8/300 with special handling > somewhere ? An independent H8/300 fix is "[PATCH v2] serial: sh-sci: byte allocated register support" (https://www.spinics.net/lists/linux-sh/msg53175.html). The main issue is: do we bother with regshift or not? If yes, we have to handle it correctly for both normal serial port handling and earlycon. For the latter, we don't have the register block size available. As of commit 2eaa790989e03900 ("earlycon: Use common framework for earlycon declarations"), DT and non-DT based earlycon have been merged, so your original commit may have impacted earlycon on non-DT based systems, too. I don't know for sure... Gr{oetje,eeting}s, Geert
diff --git a/arch/sh/kernel/cpu/sh3/setup-sh770x.c b/arch/sh/kernel/cpu/sh3/setup-sh770x.c index 59a88611df55ac8f..592cd9ab30c4272f 100644 --- a/arch/sh/kernel/cpu/sh3/setup-sh770x.c +++ b/arch/sh/kernel/cpu/sh3/setup-sh770x.c @@ -111,6 +111,7 @@ static struct platform_device rtc_device = { static struct plat_sci_port scif0_platform_data = { .type = PORT_SCI, .ops = &sh770x_sci_port_ops, + .regshift = 1, }; static struct resource scif0_resources[] = { diff --git a/arch/sh/kernel/cpu/sh4/setup-sh7750.c b/arch/sh/kernel/cpu/sh4/setup-sh7750.c index 57d30689204d03b9..d98a55416306baef 100644 --- a/arch/sh/kernel/cpu/sh4/setup-sh7750.c +++ b/arch/sh/kernel/cpu/sh4/setup-sh7750.c @@ -39,10 +39,11 @@ static struct platform_device rtc_device = { static struct plat_sci_port sci_platform_data = { .type = PORT_SCI, + .regshift = 2, }; static struct resource sci_resources[] = { - DEFINE_RES_MEM(0xffe00000, 0x20), + DEFINE_RES_MEM(0xffe00000, 0x100), DEFINE_RES_IRQ(evt2irq(0x4e0)), }; diff --git a/arch/sh/kernel/cpu/sh4/setup-sh7760.c b/arch/sh/kernel/cpu/sh4/setup-sh7760.c index e51fe1734e1368e8..0c0cdfc69dcc3e33 100644 --- a/arch/sh/kernel/cpu/sh4/setup-sh7760.c +++ b/arch/sh/kernel/cpu/sh4/setup-sh7760.c @@ -200,18 +200,12 @@ static struct platform_device scif2_device = { }; static struct plat_sci_port scif3_platform_data = { - /* - * This is actually a SIM card module serial port, based on an SCI with - * additional registers. The sh-sci driver doesn't support the SIM port - * type, declare it as a SCI. Don't declare the additional registers in - * the memory resource or the driver will compute an incorrect regshift - * value. - */ .type = PORT_SCI, + .regshift = 2, }; static struct resource scif3_resources[] = { - DEFINE_RES_MEM(0xfe480000, 0x10), + DEFINE_RES_MEM(0xfe480000, 0x100), DEFINE_RES_IRQ(evt2irq(0xc00)), DEFINE_RES_IRQ(evt2irq(0xc20)), DEFINE_RES_IRQ(evt2irq(0xc40)), diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index caf4422d9e2e59e4..955c057dff6e8c78 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -2895,15 +2895,9 @@ static int sci_init_single(struct platform_device *dev, port->type = p->type; port->flags = UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags; + port->regshift = p->regshift; port->fifosize = sci_port->params->fifosize; - if (port->type == PORT_SCI) { - if (sci_port->reg_size >= 0x20) - port->regshift = 2; - else - port->regshift = 1; - } - if (regtype == SCIx_SH4_SCIF_REGTYPE) if (sci_port->reg_size >= 0x20) port->regshift = 1; diff --git a/include/linux/serial_sci.h b/include/linux/serial_sci.h index c0e795d95477daea..eebb12fc473f49a2 100644 --- a/include/linux/serial_sci.h +++ b/include/linux/serial_sci.h @@ -57,6 +57,7 @@ struct plat_sci_port { /* * Platform overrides if necessary, defaults otherwise. */ + unsigned char regshift; unsigned char regtype; struct plat_sci_port_ops *ops;
This reverts commit dfc80387aefb78161f83732804c6d01c89c24595. Deriving the proper regshift value from the register block size is fragile, as it may have been rounded up. Furthermore we will need plat_sci_port.regshift again. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> --- arch/sh/kernel/cpu/sh3/setup-sh770x.c | 1 + arch/sh/kernel/cpu/sh4/setup-sh7750.c | 3 ++- arch/sh/kernel/cpu/sh4/setup-sh7760.c | 10 ++-------- drivers/tty/serial/sh-sci.c | 8 +------- include/linux/serial_sci.h | 1 + 5 files changed, 7 insertions(+), 16 deletions(-)