| Message ID | 20170117040336.21700-2-lokeshvutla@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Jan 17, 2017 at 09:33:32AM +0530, Lokesh Vutla wrote: > Hwmod core tries to reset and idles each IP that is registered with hwmod. > In case of earlycon, that specific uart IP cannot be reset or keep it in > idle state else earlycon hangs once hwmod resets that uart IP. So add support > to not reset uart that is being used as earlycon only if CONFIG_SERIAL_EARLYCON > is enabled. > + np = of_find_node_by_path("/chosen"); > + if (!np) > + np = of_find_node_by_path("/chosen@0"); I think you can drop the second case here. There shouldn't be an "@0" on a chosen node; core code handles that only to cater for some legacy (PPC?) DTBs, and I don't beleive it's necessary for OMAP. Thanks, Mark. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tuesday 17 January 2017 04:17 PM, Mark Rutland wrote: > On Tue, Jan 17, 2017 at 09:33:32AM +0530, Lokesh Vutla wrote: >> Hwmod core tries to reset and idles each IP that is registered with hwmod. >> In case of earlycon, that specific uart IP cannot be reset or keep it in >> idle state else earlycon hangs once hwmod resets that uart IP. So add support >> to not reset uart that is being used as earlycon only if CONFIG_SERIAL_EARLYCON >> is enabled. > >> + np = of_find_node_by_path("/chosen"); >> + if (!np) >> + np = of_find_node_by_path("/chosen@0"); > > I think you can drop the second case here. There shouldn't be an "@0" on > a chosen node; core code handles that only to cater for some legacy > (PPC?) DTBs, and I don't beleive it's necessary for OMAP. Right. Ill repost this series by dropping this case. Thanks and regards, Lokesh -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
* Lokesh Vutla <lokeshvutla@ti.com> [170116 20:06]: > Hwmod core tries to reset and idles each IP that is registered with hwmod. > In case of earlycon, that specific uart IP cannot be reset or keep it in > idle state else earlycon hangs once hwmod resets that uart IP. So add support > to not reset uart that is being used as earlycon only if CONFIG_SERIAL_EARLYCON > is enabled. Nice :) I guess this has no dependency to SERIAL_OMAP vs 8250_OMAP selection? Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wednesday 18 January 2017 04:53 AM, Tony Lindgren wrote: > * Lokesh Vutla <lokeshvutla@ti.com> [170116 20:06]: >> Hwmod core tries to reset and idles each IP that is registered with hwmod. >> In case of earlycon, that specific uart IP cannot be reset or keep it in >> idle state else earlycon hangs once hwmod resets that uart IP. So add support >> to not reset uart that is being used as earlycon only if CONFIG_SERIAL_EARLYCON >> is enabled. > > Nice :) > > I guess this has no dependency to SERIAL_OMAP vs 8250_OMAP selection? Unfortunately SERIAL_OMAP does not support earlycon yet. As I mentioned in my cover letter, I verified this series only with 8250_OMAP. Thanks and regards, Lokesh -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
* Lokesh Vutla <lokeshvutla@ti.com> [170117 19:50]: > > > On Wednesday 18 January 2017 04:53 AM, Tony Lindgren wrote: > > * Lokesh Vutla <lokeshvutla@ti.com> [170116 20:06]: > >> Hwmod core tries to reset and idles each IP that is registered with hwmod. > >> In case of earlycon, that specific uart IP cannot be reset or keep it in > >> idle state else earlycon hangs once hwmod resets that uart IP. So add support > >> to not reset uart that is being used as earlycon only if CONFIG_SERIAL_EARLYCON > >> is enabled. > > > > Nice :) > > > > I guess this has no dependency to SERIAL_OMAP vs 8250_OMAP selection? > > Unfortunately SERIAL_OMAP does not support earlycon yet. As I mentioned > in my cover letter, I verified this series only with 8250_OMAP. OK. So just to understand why it would not work with omap-serial, do we need something implemented in drivers/tty/serial/earlycon.c for non 8250 drivers to make it work? Or are there other dependencies? Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wednesday 18 January 2017 10:30 PM, Tony Lindgren wrote: > * Lokesh Vutla <lokeshvutla@ti.com> [170117 19:50]: >> >> >> On Wednesday 18 January 2017 04:53 AM, Tony Lindgren wrote: >>> * Lokesh Vutla <lokeshvutla@ti.com> [170116 20:06]: >>>> Hwmod core tries to reset and idles each IP that is registered with hwmod. >>>> In case of earlycon, that specific uart IP cannot be reset or keep it in >>>> idle state else earlycon hangs once hwmod resets that uart IP. So add support >>>> to not reset uart that is being used as earlycon only if CONFIG_SERIAL_EARLYCON >>>> is enabled. >>> >>> Nice :) >>> >>> I guess this has no dependency to SERIAL_OMAP vs 8250_OMAP selection? >> >> Unfortunately SERIAL_OMAP does not support earlycon yet. As I mentioned >> in my cover letter, I verified this series only with 8250_OMAP. > > OK. So just to understand why it would not work with omap-serial, do we > need something implemented in drivers/tty/serial/earlycon.c for non 8250 > drivers to make it work? Or are there other dependencies? Yeah, OF_EARLYCON_DECLARE should be declared for omap-serial. Just posted a patch[1] adding support for earlycon in omap-serial. [1] https://patchwork.kernel.org/patch/9525377/ Thanks and regards, Lokesh -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
* Lokesh Vutla <lokeshvutla@ti.com> [170119 02:08]: > > > On Wednesday 18 January 2017 10:30 PM, Tony Lindgren wrote: > > * Lokesh Vutla <lokeshvutla@ti.com> [170117 19:50]: > >> > >> > >> On Wednesday 18 January 2017 04:53 AM, Tony Lindgren wrote: > >>> * Lokesh Vutla <lokeshvutla@ti.com> [170116 20:06]: > >>>> Hwmod core tries to reset and idles each IP that is registered with hwmod. > >>>> In case of earlycon, that specific uart IP cannot be reset or keep it in > >>>> idle state else earlycon hangs once hwmod resets that uart IP. So add support > >>>> to not reset uart that is being used as earlycon only if CONFIG_SERIAL_EARLYCON > >>>> is enabled. > >>> > >>> Nice :) > >>> > >>> I guess this has no dependency to SERIAL_OMAP vs 8250_OMAP selection? > >> > >> Unfortunately SERIAL_OMAP does not support earlycon yet. As I mentioned > >> in my cover letter, I verified this series only with 8250_OMAP. > > > > OK. So just to understand why it would not work with omap-serial, do we > > need something implemented in drivers/tty/serial/earlycon.c for non 8250 > > drivers to make it work? Or are there other dependencies? > > Yeah, OF_EARLYCON_DECLARE should be declared for omap-serial. Just > posted a patch[1] adding support for earlycon in omap-serial. OK great. And with Vignesh's fix for omap5, I think we then have 8250-omap and omap-serial behaving the same way on all SoC variants. Regards, Tony > [1] https://patchwork.kernel.org/patch/9525377/ -- To unsubscribe from this list: send the line "unsubscribe linux-omap" 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/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c index e8b988714a09..7b1ac69a2209 100644 --- a/arch/arm/mach-omap2/omap_hwmod.c +++ b/arch/arm/mach-omap2/omap_hwmod.c @@ -3249,6 +3249,39 @@ int __init omap_hwmod_setup_one(const char *oh_name) } /** + * omap_hwmod_setup_earlycon_flags - set up flags for early console + * + * Enable DEBUG_OMAPUART_FLAGS for uart hwmod that is being used as + * early concole so that hwmod core doesn't reset and keep it in idle + * that specific uart. + */ +#ifdef CONFIG_SERIAL_EARLYCON +static void __init omap_hwmod_setup_earlycon_flags(void) +{ + struct device_node *np; + struct omap_hwmod *oh; + const char *uart; + + np = of_find_node_by_path("/chosen"); + if (!np) + np = of_find_node_by_path("/chosen@0"); + + if (np) { + uart = of_get_property(np, "stdout-path", NULL); + if (uart) { + np = of_find_node_by_path(uart); + if (np) { + uart = of_get_property(np, "ti,hwmods", NULL); + oh = omap_hwmod_lookup(uart); + if (oh) + oh->flags |= DEBUG_OMAPUART_FLAGS; + } + } + } +} +#endif + +/** * omap_hwmod_setup_all - set up all registered IP blocks * * Initialize and set up all IP blocks registered with the hwmod code. @@ -3261,6 +3294,9 @@ static int __init omap_hwmod_setup_all(void) _ensure_mpu_hwmod_is_setup(NULL); omap_hwmod_for_each(_init, NULL); +#ifdef CONFIG_SERIAL_EARLYCON + omap_hwmod_setup_earlycon_flags(); +#endif omap_hwmod_for_each(_setup, NULL); return 0;
Hwmod core tries to reset and idles each IP that is registered with hwmod. In case of earlycon, that specific uart IP cannot be reset or keep it in idle state else earlycon hangs once hwmod resets that uart IP. So add support to not reset uart that is being used as earlycon only if CONFIG_SERIAL_EARLYCON is enabled. Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com> --- arch/arm/mach-omap2/omap_hwmod.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+)