| Message ID | 20161122170616.29557-1-manu@bidouilliste.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Nov 22, 2016 at 06:06:16PM +0100, Emmanuel Vadot wrote: > The spi0 controller on the A20 have up to 4 CS (Chip Select) while the > others three only have 1. > Add the num-cs property to each node. > > Signed-off-by: Emmanuel Vadot <manu@bidouilliste.com> I don't think we have any code that uses it at the moment. What is the rationale behind this patch? Thanks! Maxime
On Thu, 24 Nov 2016 20:55:17 +0100 Maxime Ripard <maxime.ripard@free-electrons.com> wrote: > On Tue, Nov 22, 2016 at 06:06:16PM +0100, Emmanuel Vadot wrote: > > The spi0 controller on the A20 have up to 4 CS (Chip Select) while the > > others three only have 1. > > Add the num-cs property to each node. > > > > Signed-off-by: Emmanuel Vadot <manu@bidouilliste.com> > > I don't think we have any code that uses it at the moment. What is the > rationale behind this patch? > > Thanks! > Maxime > > -- > Maxime Ripard, Free Electrons > Embedded Linux and Kernel engineering > http://free-electrons.com Hi Maxime, If num-cs isn't present nothing prevent to start a transfer with a non-valid CS pin, resulting in an error. num-cs are default property especially made for this and a SPI driver should try to get the property at probe/attach time. Cheers,
On Thu, Nov 24, 2016 at 09:05:09PM +0100, Emmanuel Vadot wrote: > On Thu, 24 Nov 2016 20:55:17 +0100 > Maxime Ripard <maxime.ripard@free-electrons.com> wrote: > > > On Tue, Nov 22, 2016 at 06:06:16PM +0100, Emmanuel Vadot wrote: > > > The spi0 controller on the A20 have up to 4 CS (Chip Select) while the > > > others three only have 1. > > > Add the num-cs property to each node. > > > > > > Signed-off-by: Emmanuel Vadot <manu@bidouilliste.com> > > > > I don't think we have any code that uses it at the moment. What is the > > rationale behind this patch? > > > > Thanks! > > Maxime > > > > -- > > Maxime Ripard, Free Electrons > > Embedded Linux and Kernel engineering > > http://free-electrons.com > > Hi Maxime, > > If num-cs isn't present nothing prevent to start a transfer with a > non-valid CS pin, resulting in an error. > num-cs are default property especially made for this and a SPI driver > should try to get the property at probe/attach time. Yes, but as far as I know, our driver doesn't. I'm all in for having support for that in our driver, but without it, that patch is kind of useless. Maxime
On Fri, 25 Nov 2016 16:20:47 +0100 Maxime Ripard <maxime.ripard@free-electrons.com> wrote: > On Thu, Nov 24, 2016 at 09:05:09PM +0100, Emmanuel Vadot wrote: > > On Thu, 24 Nov 2016 20:55:17 +0100 > > Maxime Ripard <maxime.ripard@free-electrons.com> wrote: > > > > > On Tue, Nov 22, 2016 at 06:06:16PM +0100, Emmanuel Vadot wrote: > > > > The spi0 controller on the A20 have up to 4 CS (Chip Select) while the > > > > others three only have 1. > > > > Add the num-cs property to each node. > > > > > > > > Signed-off-by: Emmanuel Vadot <manu@bidouilliste.com> > > > > > > I don't think we have any code that uses it at the moment. What is the > > > rationale behind this patch? > > > > > > Thanks! > > > Maxime > > > > > > -- > > > Maxime Ripard, Free Electrons > > > Embedded Linux and Kernel engineering > > > http://free-electrons.com > > > > Hi Maxime, > > > > If num-cs isn't present nothing prevent to start a transfer with a > > non-valid CS pin, resulting in an error. > > num-cs are default property especially made for this and a SPI driver > > should try to get the property at probe/attach time. > > Yes, but as far as I know, our driver doesn't. I'm all in for having > support for that in our driver, but without it, that patch is kind of > useless. > > Maxime > > -- > Maxime Ripard, Free Electrons > Embedded Linux and Kernel engineering > http://free-electrons.com Yes the Linux driver doesn't use it but my upcoming one for FreeBSD uses it. So it is not useless for downstream user of DTS. Cheers,
Hi Emmanuel, On Fri, Nov 25, 2016 at 10:07:52PM +0100, Emmanuel Vadot wrote: > On Fri, 25 Nov 2016 16:20:47 +0100 > Maxime Ripard <maxime.ripard@free-electrons.com> wrote: > > > On Thu, Nov 24, 2016 at 09:05:09PM +0100, Emmanuel Vadot wrote: > > > On Thu, 24 Nov 2016 20:55:17 +0100 > > > Maxime Ripard <maxime.ripard@free-electrons.com> wrote: > > > > > > > On Tue, Nov 22, 2016 at 06:06:16PM +0100, Emmanuel Vadot wrote: > > > > > The spi0 controller on the A20 have up to 4 CS (Chip Select) while the > > > > > others three only have 1. > > > > > Add the num-cs property to each node. > > > > > > > > > > Signed-off-by: Emmanuel Vadot <manu@bidouilliste.com> > > > > > > > > I don't think we have any code that uses it at the moment. What is the > > > > rationale behind this patch? > > > > > > > > Thanks! > > > > Maxime > > > > > > > > -- > > > > Maxime Ripard, Free Electrons > > > > Embedded Linux and Kernel engineering > > > > http://free-electrons.com > > > > > > Hi Maxime, > > > > > > If num-cs isn't present nothing prevent to start a transfer with a > > > non-valid CS pin, resulting in an error. > > > num-cs are default property especially made for this and a SPI driver > > > should try to get the property at probe/attach time. > > > > Yes, but as far as I know, our driver doesn't. I'm all in for having > > support for that in our driver, but without it, that patch is kind of > > useless. > > Yes the Linux driver doesn't use it but my upcoming one for FreeBSD > uses it. So it is not useless for downstream user of DTS. Ah, I didn't know this was for FreeBSD. So you started to use our DTs, or do you have some modifications to it? How does that work? Anyway, the fact that it isn't used by our driver at the moment and that it's meant for other OSes should be mentionned in the commit log. Thanks! Maxime
Hi Maxime, On Thu, 1 Dec 2016 10:21:50 +0100 Maxime Ripard <maxime.ripard@free-electrons.com> wrote: > Hi Emmanuel, > > On Fri, Nov 25, 2016 at 10:07:52PM +0100, Emmanuel Vadot wrote: > > On Fri, 25 Nov 2016 16:20:47 +0100 > > Maxime Ripard <maxime.ripard@free-electrons.com> wrote: > > > > > On Thu, Nov 24, 2016 at 09:05:09PM +0100, Emmanuel Vadot wrote: > > > > On Thu, 24 Nov 2016 20:55:17 +0100 > > > > Maxime Ripard <maxime.ripard@free-electrons.com> wrote: > > > > > > > > > On Tue, Nov 22, 2016 at 06:06:16PM +0100, Emmanuel Vadot wrote: > > > > > > The spi0 controller on the A20 have up to 4 CS (Chip Select) while the > > > > > > others three only have 1. > > > > > > Add the num-cs property to each node. > > > > > > > > > > > > Signed-off-by: Emmanuel Vadot <manu@bidouilliste.com> > > > > > > > > > > I don't think we have any code that uses it at the moment. What is the > > > > > rationale behind this patch? > > > > > > > > > > Thanks! > > > > > Maxime > > > > > > > > > > -- > > > > > Maxime Ripard, Free Electrons > > > > > Embedded Linux and Kernel engineering > > > > > http://free-electrons.com > > > > > > > > Hi Maxime, > > > > > > > > If num-cs isn't present nothing prevent to start a transfer with a > > > > non-valid CS pin, resulting in an error. > > > > num-cs are default property especially made for this and a SPI driver > > > > should try to get the property at probe/attach time. > > > > > > Yes, but as far as I know, our driver doesn't. I'm all in for having > > > support for that in our driver, but without it, that patch is kind of > > > useless. > > > > Yes the Linux driver doesn't use it but my upcoming one for FreeBSD > > uses it. So it is not useless for downstream user of DTS. > > Ah, I didn't know this was for FreeBSD. So you started to use our DTs, > or do you have some modifications to it? How does that work? Yes we use the DTS from linux from quite some times now. We're currently synced with 4.7-ish. We either use them directly or modify them according to our needs and driver support. > Anyway, the fact that it isn't used by our driver at the moment and > that it's meant for other OSes should be mentionned in the commit log. Yeah I understand, I'll send a v2 with this in the commit log. > Thanks! > Maxime > > -- > Maxime Ripard, Free Electrons > Embedded Linux and Kernel engineering > http://free-electrons.com
Hi Emmanuel,
[auto build test ERROR on robh/for-next]
[also build test ERROR on v4.9-rc7 next-20161202]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Emmanuel-Vadot/ARM-dts-sunxi-Add-num-cs-for-A20-spi-nodes/20161123-034323
base: https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next
config: arm-vexpress_defconfig (attached as .config)
compiler: arm-linux-gnueabi-gcc (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=arm
All errors (new ones prefixed by >>):
>> Error: arch/arm/boot/dts/sun7i-a20.dtsi:874.13-14 syntax error
>> FATAL ERROR: Unable to parse input tree
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
On Thu, Dec 01, 2016 at 11:24:14AM +0100, Emmanuel Vadot wrote: > > > > > If num-cs isn't present nothing prevent to start a transfer > > > > > with a non-valid CS pin, resulting in an error. num-cs are > > > > > default property especially made for this and a SPI driver > > > > > should try to get the property at probe/attach time. > > > > > > > > Yes, but as far as I know, our driver doesn't. I'm all in for > > > > having support for that in our driver, but without it, that > > > > patch is kind of useless. > > > > > > Yes the Linux driver doesn't use it but my upcoming one for FreeBSD > > > uses it. So it is not useless for downstream user of DTS. > > > > Ah, I didn't know this was for FreeBSD. So you started to use our DTs, > > or do you have some modifications to it? How does that work? > > Yes we use the DTS from linux from quite some times now. We're > currently synced with 4.7-ish. We either use them directly or > modify them according to our needs and driver support. Do you have a link to those modifications? Thanks, Maxime
On Mon, 5 Dec 2016 10:28:21 +0100 Maxime Ripard <maxime.ripard@free-electrons.com> wrote: > On Thu, Dec 01, 2016 at 11:24:14AM +0100, Emmanuel Vadot wrote: > > > > > > If num-cs isn't present nothing prevent to start a transfer > > > > > > with a non-valid CS pin, resulting in an error. num-cs are > > > > > > default property especially made for this and a SPI driver > > > > > > should try to get the property at probe/attach time. > > > > > > > > > > Yes, but as far as I know, our driver doesn't. I'm all in for > > > > > having support for that in our driver, but without it, that > > > > > patch is kind of useless. > > > > > > > > Yes the Linux driver doesn't use it but my upcoming one for FreeBSD > > > > uses it. So it is not useless for downstream user of DTS. > > > > > > Ah, I didn't know this was for FreeBSD. So you started to use our DTs, > > > or do you have some modifications to it? How does that work? > > > > Yes we use the DTS from linux from quite some times now. We're > > currently synced with 4.7-ish. We either use them directly or > > modify them according to our needs and driver support. > > Do you have a link to those modifications? > > Thanks, > Maxime > > -- > Maxime Ripard, Free Electrons > Embedded Linux and Kernel engineering > http://free-electrons.com Sure, https://svnweb.freebsd.org/base/head/sys/boot/fdt/dts/arm/
diff --git a/arch/arm/boot/dts/sun7i-a20.dtsi b/arch/arm/boot/dts/sun7i-a20.dtsi index 94cf5a1..ed21982 100644 --- a/arch/arm/boot/dts/sun7i-a20.dtsi +++ b/arch/arm/boot/dts/sun7i-a20.dtsi @@ -871,6 +871,7 @@ status = "disabled"; #address-cells = <1>; #size-cells = <0>; + num-cs = 4; }; spi1: spi@01c06000 { @@ -885,6 +886,7 @@ status = "disabled"; #address-cells = <1>; #size-cells = <0>; + num-cs = 1; }; emac: ethernet@01c0b000 { @@ -1037,6 +1039,7 @@ status = "disabled"; #address-cells = <1>; #size-cells = <0>; + num-cs = 1; }; ahci: sata@01c18000 { @@ -1079,6 +1082,7 @@ status = "disabled"; #address-cells = <1>; #size-cells = <0>; + num-cs = 1; }; pio: pinctrl@01c20800 {
The spi0 controller on the A20 have up to 4 CS (Chip Select) while the others three only have 1. Add the num-cs property to each node. Signed-off-by: Emmanuel Vadot <manu@bidouilliste.com> --- arch/arm/boot/dts/sun7i-a20.dtsi | 4 ++++ 1 file changed, 4 insertions(+)