| Message ID | 1468545873-134339-1-git-send-email-briannorris@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Am Donnerstag, 14. Juli 2016, 18:24:33 schrieb Brian Norris: > It's nicer to see this: > > # ls -l /sys/bus/spi/devices/ > total 0 > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi0.0 -> > ../../../devices/platform/ff1c0000.spi/spi_master/spi0/spi0.0 lrwxrwxrwx 1 > root root 0 Dec 31 1969 spi1.0 -> > ../../../devices/platform/ff1d0000.spi/spi_master/spi1/spi1.0 lrwxrwxrwx 1 > root root 0 Dec 31 1969 spi2.0 -> > ../../../devices/platform/ff1e0000.spi/spi_master/spi2/spi2.0 lrwxrwxrwx 1 > root root 0 Dec 31 1969 spi5.0 -> > ../../../devices/platform/ff200000.spi/spi_master/spi5/spi5.0 > > than this: > > # ls -l /sys/bus/spi/devices/ > total 0 > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32763.0 -> > ../../../devices/platform/ff200000.spi/spi_master/spi32763/spi32763.0 > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32764.0 -> > ../../../devices/platform/ff1e0000.spi/spi_master/spi32764/spi32764.0 > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32765.0 -> > ../../../devices/platform/ff1d0000.spi/spi_master/spi32765/spi32765.0 > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32766.0 -> > ../../../devices/platform/ff1c0000.spi/spi_master/spi32766/spi32766.0 > > With the latter, it's much clearer which bus devices are on. > > Signed-off-by: Brian Norris <briannorris@chromium.org> applied for 4.9 Thanks Heiko
Hello, On Thu, Jul 14, 2016 at 06:24:33PM -0700, Brian Norris wrote: > It's nicer to see this: > > # ls -l /sys/bus/spi/devices/ > total 0 > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi0.0 -> ../../../devices/platform/ff1c0000.spi/spi_master/spi0/spi0.0 > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi1.0 -> ../../../devices/platform/ff1d0000.spi/spi_master/spi1/spi1.0 > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi2.0 -> ../../../devices/platform/ff1e0000.spi/spi_master/spi2/spi2.0 > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi5.0 -> ../../../devices/platform/ff200000.spi/spi_master/spi5/spi5.0 > > than this: > > # ls -l /sys/bus/spi/devices/ > total 0 > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32763.0 -> ../../../devices/platform/ff200000.spi/spi_master/spi32763/spi32763.0 > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32764.0 -> ../../../devices/platform/ff1e0000.spi/spi_master/spi32764/spi32764.0 > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32765.0 -> ../../../devices/platform/ff1d0000.spi/spi_master/spi32765/spi32765.0 > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32766.0 -> ../../../devices/platform/ff1c0000.spi/spi_master/spi32766/spi32766.0 > > With the latter, it's much clearer which bus devices are on. > > Signed-off-by: Brian Norris <briannorris@chromium.org> > --- > arch/arm64/boot/dts/rockchip/rk3399.dtsi | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/arch/arm64/boot/dts/rockchip/rk3399.dtsi b/arch/arm64/boot/dts/rockchip/rk3399.dtsi > index 4c84229789ef..b04abbfd4898 100644 > --- a/arch/arm64/boot/dts/rockchip/rk3399.dtsi > +++ b/arch/arm64/boot/dts/rockchip/rk3399.dtsi > @@ -70,6 +70,12 @@ > serial2 = &uart2; > serial3 = &uart3; > serial4 = &uart4; > + spi0 = &spi0; > + spi1 = &spi1; > + spi2 = &spi2; > + spi3 = &spi3; > + spi4 = &spi4; > + spi5 = &spi5; Note that Rob Herring (with his dt-maintainer hat on) doesn't like these aliases. See for example: http://mid.gmane.org/20160705140546.GA10601@rob-hp-laptop Best regards Uwe
Hi Uwe, Am Dienstag, 19. Juli 2016, 08:39:55 schrieb Uwe Kleine-König: > On Thu, Jul 14, 2016 at 06:24:33PM -0700, Brian Norris wrote: > > It's nicer to see this: > > # ls -l /sys/bus/spi/devices/ > > total 0 > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi0.0 -> > > ../../../devices/platform/ff1c0000.spi/spi_master/spi0/spi0.0 > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi1.0 -> > > ../../../devices/platform/ff1d0000.spi/spi_master/spi1/spi1.0 > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi2.0 -> > > ../../../devices/platform/ff1e0000.spi/spi_master/spi2/spi2.0 > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi5.0 -> > > ../../../devices/platform/ff200000.spi/spi_master/spi5/spi5.0> > > than this: > > # ls -l /sys/bus/spi/devices/ > > total 0 > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32763.0 -> > > ../../../devices/platform/ff200000.spi/spi_master/spi32763/spi32763.0 > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32764.0 -> > > ../../../devices/platform/ff1e0000.spi/spi_master/spi32764/spi32764.0 > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32765.0 -> > > ../../../devices/platform/ff1d0000.spi/spi_master/spi32765/spi32765.0 > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32766.0 -> > > ../../../devices/platform/ff1c0000.spi/spi_master/spi32766/spi32766.0> > > With the latter, it's much clearer which bus devices are on. > > > > Signed-off-by: Brian Norris <briannorris@chromium.org> > > --- > > > > arch/arm64/boot/dts/rockchip/rk3399.dtsi | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/arch/arm64/boot/dts/rockchip/rk3399.dtsi > > b/arch/arm64/boot/dts/rockchip/rk3399.dtsi index > > 4c84229789ef..b04abbfd4898 100644 > > --- a/arch/arm64/boot/dts/rockchip/rk3399.dtsi > > +++ b/arch/arm64/boot/dts/rockchip/rk3399.dtsi > > @@ -70,6 +70,12 @@ > > > > serial2 = &uart2; > > serial3 = &uart3; > > serial4 = &uart4; > > > > + spi0 = &spi0; > > + spi1 = &spi1; > > + spi2 = &spi2; > > + spi3 = &spi3; > > + spi4 = &spi4; > > + spi5 = &spi5; > > Note that Rob Herring (with his dt-maintainer hat on) doesn't like these > aliases. > See for example: > http://mid.gmane.org/20160705140546.GA10601@rob-hp-laptop thanks for the heads up on this. I've dropped this patch again. Thanks Heiko
+ Rob Hi, On Tue, Jul 19, 2016 at 08:56:47PM +0200, Heiko Stuebner wrote: > Am Dienstag, 19. Juli 2016, 08:39:55 schrieb Uwe Kleine-König: > > On Thu, Jul 14, 2016 at 06:24:33PM -0700, Brian Norris wrote: > > > It's nicer to see this: > > > # ls -l /sys/bus/spi/devices/ > > > total 0 > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi0.0 -> > > > ../../../devices/platform/ff1c0000.spi/spi_master/spi0/spi0.0 > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi1.0 -> > > > ../../../devices/platform/ff1d0000.spi/spi_master/spi1/spi1.0 > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi2.0 -> > > > ../../../devices/platform/ff1e0000.spi/spi_master/spi2/spi2.0 > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi5.0 -> > > > ../../../devices/platform/ff200000.spi/spi_master/spi5/spi5.0> > > > than this: > > > # ls -l /sys/bus/spi/devices/ > > > total 0 > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32763.0 -> > > > ../../../devices/platform/ff200000.spi/spi_master/spi32763/spi32763.0 > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32764.0 -> > > > ../../../devices/platform/ff1e0000.spi/spi_master/spi32764/spi32764.0 > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32765.0 -> > > > ../../../devices/platform/ff1d0000.spi/spi_master/spi32765/spi32765.0 > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32766.0 -> > > > ../../../devices/platform/ff1c0000.spi/spi_master/spi32766/spi32766.0> > > > With the latter, it's much clearer which bus devices are on. > > > > > > Signed-off-by: Brian Norris <briannorris@chromium.org> > > > --- > > > > > > arch/arm64/boot/dts/rockchip/rk3399.dtsi | 6 ++++++ > > > 1 file changed, 6 insertions(+) > > > > > > diff --git a/arch/arm64/boot/dts/rockchip/rk3399.dtsi > > > b/arch/arm64/boot/dts/rockchip/rk3399.dtsi index > > > 4c84229789ef..b04abbfd4898 100644 > > > --- a/arch/arm64/boot/dts/rockchip/rk3399.dtsi > > > +++ b/arch/arm64/boot/dts/rockchip/rk3399.dtsi > > > @@ -70,6 +70,12 @@ > > > > > > serial2 = &uart2; > > > serial3 = &uart3; > > > serial4 = &uart4; > > > > > > + spi0 = &spi0; > > > + spi1 = &spi1; > > > + spi2 = &spi2; > > > + spi3 = &spi3; > > > + spi4 = &spi4; > > > + spi5 = &spi5; > > > > Note that Rob Herring (with his dt-maintainer hat on) doesn't like these > > aliases. > > See for example: > > http://mid.gmane.org/20160705140546.GA10601@rob-hp-laptop But why? I believe half the arguments in the linked thread were Catch-22's -- there were no "mainline" users (which is a false target IMO anyway, as Christer Weinigel mentioned somewhere in the thread Rob linked), and so we couldn't accept more documentation (or users) for the feature. FWIW, my quick grep now shows there are currently 43 mainline users. This feature is very useful. Some of the thread Rob pointed to argued that the indexing isn't HW documentation; in this case, it most certainly is. The RK3399 TRM explicitly has these SPI buses named SPI0, SPI1, SPI2, SPI3, SPI4, and SPI5, and schematics that I've seen use the same terminology. It is therefore *much* nicer to have my device show up as 'spi2.0' (reflecting their correct HW name) rather than spi32764.0. Sometimes I can't even get as far as mounting sysfs to check what this maps to, but having spi2.0 in the kernel log can clearly tell me what device is causing problems. If Rob can support a better alternative solution, I'd be happy to switch. But I don't understand why we can't use a useful (not just to me, but presumably to at least 43 other independent users, and many more out of tree), existing, and long-supported feature here. > thanks for the heads up on this. I've dropped this patch again. :( Regards, Brian
On Tue, Jul 19, 2016 at 12:27:54PM -0700, Brian Norris wrote: > + Rob + Rob for real > Hi, > > On Tue, Jul 19, 2016 at 08:56:47PM +0200, Heiko Stuebner wrote: > > Am Dienstag, 19. Juli 2016, 08:39:55 schrieb Uwe Kleine-König: > > > On Thu, Jul 14, 2016 at 06:24:33PM -0700, Brian Norris wrote: > > > > It's nicer to see this: > > > > # ls -l /sys/bus/spi/devices/ > > > > total 0 > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi0.0 -> > > > > ../../../devices/platform/ff1c0000.spi/spi_master/spi0/spi0.0 > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi1.0 -> > > > > ../../../devices/platform/ff1d0000.spi/spi_master/spi1/spi1.0 > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi2.0 -> > > > > ../../../devices/platform/ff1e0000.spi/spi_master/spi2/spi2.0 > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi5.0 -> > > > > ../../../devices/platform/ff200000.spi/spi_master/spi5/spi5.0> > > > > than this: > > > > # ls -l /sys/bus/spi/devices/ > > > > total 0 > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32763.0 -> > > > > ../../../devices/platform/ff200000.spi/spi_master/spi32763/spi32763.0 > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32764.0 -> > > > > ../../../devices/platform/ff1e0000.spi/spi_master/spi32764/spi32764.0 > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32765.0 -> > > > > ../../../devices/platform/ff1d0000.spi/spi_master/spi32765/spi32765.0 > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32766.0 -> > > > > ../../../devices/platform/ff1c0000.spi/spi_master/spi32766/spi32766.0> > > > > With the latter, it's much clearer which bus devices are on. > > > > > > > > Signed-off-by: Brian Norris <briannorris@chromium.org> > > > > --- > > > > > > > > arch/arm64/boot/dts/rockchip/rk3399.dtsi | 6 ++++++ > > > > 1 file changed, 6 insertions(+) > > > > > > > > diff --git a/arch/arm64/boot/dts/rockchip/rk3399.dtsi > > > > b/arch/arm64/boot/dts/rockchip/rk3399.dtsi index > > > > 4c84229789ef..b04abbfd4898 100644 > > > > --- a/arch/arm64/boot/dts/rockchip/rk3399.dtsi > > > > +++ b/arch/arm64/boot/dts/rockchip/rk3399.dtsi > > > > @@ -70,6 +70,12 @@ > > > > > > > > serial2 = &uart2; > > > > serial3 = &uart3; > > > > serial4 = &uart4; > > > > > > > > + spi0 = &spi0; > > > > + spi1 = &spi1; > > > > + spi2 = &spi2; > > > > + spi3 = &spi3; > > > > + spi4 = &spi4; > > > > + spi5 = &spi5; > > > > > > Note that Rob Herring (with his dt-maintainer hat on) doesn't like these > > > aliases. > > > See for example: > > > http://mid.gmane.org/20160705140546.GA10601@rob-hp-laptop > > But why? I believe half the arguments in the linked thread were > Catch-22's -- there were no "mainline" users (which is a false target > IMO anyway, as Christer Weinigel mentioned somewhere in the thread Rob > linked), and so we couldn't accept more documentation (or users) for the > feature. FWIW, my quick grep now shows there are currently 43 mainline > users. > > This feature is very useful. Some of the thread Rob pointed to argued > that the indexing isn't HW documentation; in this case, it most > certainly is. The RK3399 TRM explicitly has these SPI buses named SPI0, > SPI1, SPI2, SPI3, SPI4, and SPI5, and schematics that I've seen use the > same terminology. It is therefore *much* nicer to have my device show up > as 'spi2.0' (reflecting their correct HW name) rather than spi32764.0. > Sometimes I can't even get as far as mounting sysfs to check what this > maps to, but having spi2.0 in the kernel log can clearly tell me what > device is causing problems. > > If Rob can support a better alternative solution, I'd be happy to > switch. But I don't understand why we can't use a useful (not just to > me, but presumably to at least 43 other independent users, and many > more out of tree), existing, and long-supported feature here. > > > thanks for the heads up on this. I've dropped this patch again. > > :( > > Regards, > Brian
Am Dienstag, 19. Juli 2016, 12:29:14 schrieb Brian Norris: > On Tue, Jul 19, 2016 at 12:27:54PM -0700, Brian Norris wrote: > > + Rob > > + Rob for real > > > Hi, > > > > On Tue, Jul 19, 2016 at 08:56:47PM +0200, Heiko Stuebner wrote: > > > Am Dienstag, 19. Juli 2016, 08:39:55 schrieb Uwe Kleine-König: > > > > On Thu, Jul 14, 2016 at 06:24:33PM -0700, Brian Norris wrote: > > > > > It's nicer to see this: > > > > > # ls -l /sys/bus/spi/devices/ > > > > > total 0 > > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi0.0 -> > > > > > ../../../devices/platform/ff1c0000.spi/spi_master/spi0/spi0.0 > > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi1.0 -> > > > > > ../../../devices/platform/ff1d0000.spi/spi_master/spi1/spi1.0 > > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi2.0 -> > > > > > ../../../devices/platform/ff1e0000.spi/spi_master/spi2/spi2.0 > > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi5.0 -> > > > > > ../../../devices/platform/ff200000.spi/spi_master/spi5/spi5.0> > > > > > > > > > > than this: > > > > > # ls -l /sys/bus/spi/devices/ > > > > > total 0 > > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32763.0 -> > > > > > ../../../devices/platform/ff200000.spi/spi_master/spi32763/spi32 > > > > > 763.0 > > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32764.0 -> > > > > > ../../../devices/platform/ff1e0000.spi/spi_master/spi32764/spi32 > > > > > 764.0 > > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32765.0 -> > > > > > ../../../devices/platform/ff1d0000.spi/spi_master/spi32765/spi32 > > > > > 765.0 > > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32766.0 -> > > > > > ../../../devices/platform/ff1c0000.spi/spi_master/spi32766/spi32 > > > > > 766.0> > > > > > > > > > > With the latter, it's much clearer which bus devices are on. > > > > > > > > > > Signed-off-by: Brian Norris <briannorris@chromium.org> > > > > > --- > > > > > > > > > > arch/arm64/boot/dts/rockchip/rk3399.dtsi | 6 ++++++ > > > > > 1 file changed, 6 insertions(+) > > > > > > > > > > diff --git a/arch/arm64/boot/dts/rockchip/rk3399.dtsi > > > > > b/arch/arm64/boot/dts/rockchip/rk3399.dtsi index > > > > > 4c84229789ef..b04abbfd4898 100644 > > > > > --- a/arch/arm64/boot/dts/rockchip/rk3399.dtsi > > > > > +++ b/arch/arm64/boot/dts/rockchip/rk3399.dtsi > > > > > @@ -70,6 +70,12 @@ > > > > > > > > > > serial2 = &uart2; > > > > > serial3 = &uart3; > > > > > serial4 = &uart4; > > > > > > > > > > + spi0 = &spi0; > > > > > + spi1 = &spi1; > > > > > + spi2 = &spi2; > > > > > + spi3 = &spi3; > > > > > + spi4 = &spi4; > > > > > + spi5 = &spi5; > > > > > > > > Note that Rob Herring (with his dt-maintainer hat on) doesn't like > > > > these > > > > aliases. > > > > > > > > See for example: > > > > http://mid.gmane.org/20160705140546.GA10601@rob-hp-laptop > > > > But why? I believe half the arguments in the linked thread were > > Catch-22's -- there were no "mainline" users (which is a false target > > IMO anyway, as Christer Weinigel mentioned somewhere in the thread Rob > > linked), and so we couldn't accept more documentation (or users) for the > > feature. FWIW, my quick grep now shows there are currently 43 mainline > > users. > > > > This feature is very useful. Some of the thread Rob pointed to argued > > that the indexing isn't HW documentation; in this case, it most > > certainly is. The RK3399 TRM explicitly has these SPI buses named SPI0, > > SPI1, SPI2, SPI3, SPI4, and SPI5, and schematics that I've seen use the > > same terminology. It is therefore *much* nicer to have my device show up > > as 'spi2.0' (reflecting their correct HW name) rather than spi32764.0. > > Sometimes I can't even get as far as mounting sysfs to check what this > > maps to, but having spi2.0 in the kernel log can clearly tell me what > > device is causing problems. > > > > If Rob can support a better alternative solution, I'd be happy to > > switch. But I don't understand why we can't use a useful (not just to > > me, but presumably to at least 43 other independent users, and many > > more out of tree), existing, and long-supported feature here. Personally, I don't have any real opinion on this but the argument sounds plausible to me (aka they are named with numbers in every manual, schematics) so it might be helpful to have that around - similar to i2c that is in the dtsi already. I think I remember Doug having a similar discussion around mmc-aliases some time ago - that met opposition as well [0] - although I guess the numbering was a bit more arbitary there. I guess we'll just see what Rob says. Heiko [0] https://lkml.org/lkml/2016/4/29/610
Am Mittwoch, 20. Juli 2016, 00:18:40 schrieb Heiko Stübner: > Am Dienstag, 19. Juli 2016, 12:29:14 schrieb Brian Norris: > > On Tue, Jul 19, 2016 at 12:27:54PM -0700, Brian Norris wrote: > > > + Rob > > > > + Rob for real > > > > > Hi, > > > > > > On Tue, Jul 19, 2016 at 08:56:47PM +0200, Heiko Stuebner wrote: > > > > Am Dienstag, 19. Juli 2016, 08:39:55 schrieb Uwe Kleine-König: > > > > > On Thu, Jul 14, 2016 at 06:24:33PM -0700, Brian Norris wrote: > > > > > > It's nicer to see this: > > > > > > # ls -l /sys/bus/spi/devices/ > > > > > > total 0 > > > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi0.0 -> > > > > > > ../../../devices/platform/ff1c0000.spi/spi_master/spi0/spi0.0 > > > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi1.0 -> > > > > > > ../../../devices/platform/ff1d0000.spi/spi_master/spi1/spi1.0 > > > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi2.0 -> > > > > > > ../../../devices/platform/ff1e0000.spi/spi_master/spi2/spi2.0 > > > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi5.0 -> > > > > > > ../../../devices/platform/ff200000.spi/spi_master/spi5/spi5.0> > > > > > > > > > > > > than this: > > > > > > # ls -l /sys/bus/spi/devices/ > > > > > > total 0 > > > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32763.0 -> > > > > > > ../../../devices/platform/ff200000.spi/spi_master/spi32763/spi > > > > > > 32 > > > > > > 763.0 > > > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32764.0 -> > > > > > > ../../../devices/platform/ff1e0000.spi/spi_master/spi32764/spi > > > > > > 32 > > > > > > 764.0 > > > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32765.0 -> > > > > > > ../../../devices/platform/ff1d0000.spi/spi_master/spi32765/spi > > > > > > 32 > > > > > > 765.0 > > > > > > lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32766.0 -> > > > > > > ../../../devices/platform/ff1c0000.spi/spi_master/spi32766/spi > > > > > > 32 > > > > > > 766.0> > > > > > > > > > > > > With the latter, it's much clearer which bus devices are on. > > > > > > > > > > > > Signed-off-by: Brian Norris <briannorris@chromium.org> > > > > > > --- > > > > > > > > > > > > arch/arm64/boot/dts/rockchip/rk3399.dtsi | 6 ++++++ > > > > > > 1 file changed, 6 insertions(+) > > > > > > > > > > > > diff --git a/arch/arm64/boot/dts/rockchip/rk3399.dtsi > > > > > > b/arch/arm64/boot/dts/rockchip/rk3399.dtsi index > > > > > > 4c84229789ef..b04abbfd4898 100644 > > > > > > --- a/arch/arm64/boot/dts/rockchip/rk3399.dtsi > > > > > > +++ b/arch/arm64/boot/dts/rockchip/rk3399.dtsi > > > > > > @@ -70,6 +70,12 @@ > > > > > > > > > > > > serial2 = &uart2; > > > > > > serial3 = &uart3; > > > > > > serial4 = &uart4; > > > > > > > > > > > > + spi0 = &spi0; > > > > > > + spi1 = &spi1; > > > > > > + spi2 = &spi2; > > > > > > + spi3 = &spi3; > > > > > > + spi4 = &spi4; > > > > > > + spi5 = &spi5; > > > > > > > > > > Note that Rob Herring (with his dt-maintainer hat on) doesn't like > > > > > these > > > > > aliases. > > > > > > > > > > See for example: > > > > > http://mid.gmane.org/20160705140546.GA10601@rob-hp-laptop > > > > > > But why? I believe half the arguments in the linked thread were > > > Catch-22's -- there were no "mainline" users (which is a false target > > > IMO anyway, as Christer Weinigel mentioned somewhere in the thread Rob > > > linked), and so we couldn't accept more documentation (or users) for the > > > feature. FWIW, my quick grep now shows there are currently 43 mainline > > > users. > > > > > > This feature is very useful. Some of the thread Rob pointed to argued > > > that the indexing isn't HW documentation; in this case, it most > > > certainly is. The RK3399 TRM explicitly has these SPI buses named SPI0, > > > SPI1, SPI2, SPI3, SPI4, and SPI5, and schematics that I've seen use the > > > same terminology. It is therefore *much* nicer to have my device show up > > > as 'spi2.0' (reflecting their correct HW name) rather than spi32764.0. > > > Sometimes I can't even get as far as mounting sysfs to check what this > > > maps to, but having spi2.0 in the kernel log can clearly tell me what > > > device is causing problems. > > > > > > If Rob can support a better alternative solution, I'd be happy to > > > switch. But I don't understand why we can't use a useful (not just to > > > me, but presumably to at least 43 other independent users, and many > > > more out of tree), existing, and long-supported feature here. > > Personally, I don't have any real opinion on this but the argument sounds > plausible to me (aka they are named with numbers in every manual, > schematics) so it might be helpful to have that around - similar to i2c > that is in the dtsi already. > > I think I remember Doug having a similar discussion around mmc-aliases some > time ago - that met opposition as well [0] - although I guess the numbering > was a bit more arbitary there. > > I guess we'll just see what Rob says. Uwe pointed me to a very similar discussion and response from Rob about spi aliases at: https://lkml.org/lkml/2016/5/25/566
+ Mark On Wed, Jul 20, 2016 at 10:11:11AM +0200, Heiko Stuebner wrote: > Am Mittwoch, 20. Juli 2016, 00:18:40 schrieb Heiko Stübner: > > Am Dienstag, 19. Juli 2016, 12:29:14 schrieb Brian Norris: > > > On Tue, Jul 19, 2016 at 12:27:54PM -0700, Brian Norris wrote: > > > > On Tue, Jul 19, 2016 at 08:56:47PM +0200, Heiko Stuebner wrote: > > > > > Am Dienstag, 19. Juli 2016, 08:39:55 schrieb Uwe Kleine-König: > > > > > > > --- a/arch/arm64/boot/dts/rockchip/rk3399.dtsi > > > > > > > +++ b/arch/arm64/boot/dts/rockchip/rk3399.dtsi > > > > > > > @@ -70,6 +70,12 @@ > > > > > > > > > > > > > > serial2 = &uart2; > > > > > > > serial3 = &uart3; > > > > > > > serial4 = &uart4; > > > > > > > > > > > > > > + spi0 = &spi0; > > > > > > > + spi1 = &spi1; > > > > > > > + spi2 = &spi2; > > > > > > > + spi3 = &spi3; > > > > > > > + spi4 = &spi4; > > > > > > > + spi5 = &spi5; > > > > > > > > > > > > Note that Rob Herring (with his dt-maintainer hat on) doesn't like > > > > > > these > > > > > > aliases. > > > > > > > > > > > > See for example: > > > > > > http://mid.gmane.org/20160705140546.GA10601@rob-hp-laptop > > > > > > > > But why? I believe half the arguments in the linked thread were > > > > Catch-22's -- there were no "mainline" users (which is a false target > > > > IMO anyway, as Christer Weinigel mentioned somewhere in the thread Rob > > > > linked), and so we couldn't accept more documentation (or users) for the > > > > feature. FWIW, my quick grep now shows there are currently 43 mainline > > > > users. > > > > > > > > This feature is very useful. Some of the thread Rob pointed to argued > > > > that the indexing isn't HW documentation; in this case, it most > > > > certainly is. The RK3399 TRM explicitly has these SPI buses named SPI0, > > > > SPI1, SPI2, SPI3, SPI4, and SPI5, and schematics that I've seen use the > > > > same terminology. It is therefore *much* nicer to have my device show up > > > > as 'spi2.0' (reflecting their correct HW name) rather than spi32764.0. > > > > Sometimes I can't even get as far as mounting sysfs to check what this > > > > maps to, but having spi2.0 in the kernel log can clearly tell me what > > > > device is causing problems. > > > > > > > > If Rob can support a better alternative solution, I'd be happy to > > > > switch. But I don't understand why we can't use a useful (not just to > > > > me, but presumably to at least 43 other independent users, and many > > > > more out of tree), existing, and long-supported feature here. > > > > Personally, I don't have any real opinion on this but the argument sounds > > plausible to me (aka they are named with numbers in every manual, > > schematics) so it might be helpful to have that around - similar to i2c > > that is in the dtsi already. > > > > I think I remember Doug having a similar discussion around mmc-aliases some > > time ago - that met opposition as well [0] - although I guess the numbering > > was a bit more arbitary there. > > > > I guess we'll just see what Rob says. > > Uwe pointed me to a very similar discussion and response from Rob about spi > aliases at: > https://lkml.org/lkml/2016/5/25/566 I had read that already. I figured that was just rationale for not documenting the feature (still silly IMO), and not for avoiding using the existing feature. What is this "label" feature Rob speaks of? Does it exist in practice (AFAICT the answer is "no")? The description doesn't seem terrible, depending on the implementation. Would that become the actual device name (i.e., dev_name(dev))? Or just a filesystem symlink? And how does one assign such a label? Brian
On Fri, Jul 29, 2016 at 04:39:51PM -0700, Brian Norris wrote: > + Mark I very nearly deleted this unread based on the subject line... > I had read that already. I figured that was just rationale for not > documenting the feature (still silly IMO), and not for avoiding using > the existing feature. All in tree aliases provided for SPI buses are strings so if we're doing anything with aliases we really ought to be parsing them as strings not numbers (they're people describing the use of buses on their board). I quite seriously am more inclined to remove the numbering functionality as stands than document it as stands given how many layers of implementation specifics are required to make practical use of it and the existing practical use for human readable purposes, all we're doing is trying to be helpful with some random string we found somewhere and we don't want to encourage people to do that rather than doing what they're currently doing any providing human readable names. We shouldn't preclude being more helpful if we get better ideas and we shouldn't encourage people to make bad decisions about identifying things from userspace. Or I suppose we could go the way of all standards and document useful behaviour without implementing it but that doesn't seem awesome either. > What is this "label" feature Rob speaks of? Does it exist in practice > (AFAICT the answer is "no")? The description doesn't seem terrible, It's a property called "label" which is a standard thing in DT for providing descriptive labels, if you look in git you can see quite a few examples for other subsystems. I'd expect to see it show up in the string for the device name in place of the numbers (both if used for a device, the bus number for the bus). Nobody has written any code yet, I've never personally found the motivation and nobody sent me any patches. > depending on the implementation. Would that become the actual device > name (i.e., dev_name(dev))? Or just a filesystem symlink? And how does > one assign such a label? It should really show up in dev_name() since for most devices it'll be more likely to show up in a log message than anywhere else.
diff --git a/arch/arm64/boot/dts/rockchip/rk3399.dtsi b/arch/arm64/boot/dts/rockchip/rk3399.dtsi index 4c84229789ef..b04abbfd4898 100644 --- a/arch/arm64/boot/dts/rockchip/rk3399.dtsi +++ b/arch/arm64/boot/dts/rockchip/rk3399.dtsi @@ -70,6 +70,12 @@ serial2 = &uart2; serial3 = &uart3; serial4 = &uart4; + spi0 = &spi0; + spi1 = &spi1; + spi2 = &spi2; + spi3 = &spi3; + spi4 = &spi4; + spi5 = &spi5; }; cpus {
It's nicer to see this: # ls -l /sys/bus/spi/devices/ total 0 lrwxrwxrwx 1 root root 0 Dec 31 1969 spi0.0 -> ../../../devices/platform/ff1c0000.spi/spi_master/spi0/spi0.0 lrwxrwxrwx 1 root root 0 Dec 31 1969 spi1.0 -> ../../../devices/platform/ff1d0000.spi/spi_master/spi1/spi1.0 lrwxrwxrwx 1 root root 0 Dec 31 1969 spi2.0 -> ../../../devices/platform/ff1e0000.spi/spi_master/spi2/spi2.0 lrwxrwxrwx 1 root root 0 Dec 31 1969 spi5.0 -> ../../../devices/platform/ff200000.spi/spi_master/spi5/spi5.0 than this: # ls -l /sys/bus/spi/devices/ total 0 lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32763.0 -> ../../../devices/platform/ff200000.spi/spi_master/spi32763/spi32763.0 lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32764.0 -> ../../../devices/platform/ff1e0000.spi/spi_master/spi32764/spi32764.0 lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32765.0 -> ../../../devices/platform/ff1d0000.spi/spi_master/spi32765/spi32765.0 lrwxrwxrwx 1 root root 0 Dec 31 1969 spi32766.0 -> ../../../devices/platform/ff1c0000.spi/spi_master/spi32766/spi32766.0 With the latter, it's much clearer which bus devices are on. Signed-off-by: Brian Norris <briannorris@chromium.org> --- arch/arm64/boot/dts/rockchip/rk3399.dtsi | 6 ++++++ 1 file changed, 6 insertions(+)