From 7db143b89137de06ed289cf8b302f3bbbc5baa1f Mon Sep 17 00:00:00 2001 From: Tony Lindgren Date: Tue, 16 Sep 2014 15:09:44 -0700 Subject: ARM: OMAP3: Fix I/O chain clock line assertion timed out error We are getting "PRM: I/O chain clock line assertion timed out" errors on early omaps for device tree based booting. This is because we are unconditionally calling reconfigure_io_chain while legacy booting has omap3_has_io_chain_ctrl() checks in place in omap_hwmod.c. For device tree based booting, we are calling reconfigure_io_chain unconditionally from pinctrl framework. So we need to add a check for omap3_has_io_chain_ctrl() to avoid the errors for trying to access a register that does not exist. For es3.0, the documentation in "4.11.2 Device Off-Mode Configuration" just mentions PM_WKEN_WKUP[8] bit. For es3.1, there's a new chapter in documentation for "4.11.2.2 I/O Wake-Up Mechanism" that describes the PM_WKEN_WKUP[16] ST_IO_CHAIN bit. So PM_WKEN_WKUP[16] bit did not get added until in es3.1 probaly to fix issues with flakey wake-up events. We are doing proper checks for ST_IO_CHAIN already in id.c and with omap3_has_io_chain_ctrl(). For more information, see also commit b02b917211d5 ("ARM: OMAP3: PM: fix I/O wakeup and I/O chain clock control detection"). Let's fix the issue by selecting the right function during init for reconfigure_io_chain depending on the omap revision. For es3.0 and earlier we need to just toggle EN_IO. By doing this, we can move the check for omap3_has_io_chain_ctrl() from omap_hwmod.c to the init code in prm_3xxx.c. And then we can unconditionally call reconfigure_io_chain. Thanks to Paul Walmsley and Nishanth Menon for help with debugging the issue. Fixes: 30a69ef785e8 ("ARM: OMAP: Move DT wake-up event handling over to use pinctrl-single-omap") Cc: Kevin Hilman Cc: Paul Walmsley Cc: Tero Kristo Reviewed-by: Nishanth Menon Signed-off-by: Tony Lindgren --- arch/arm/mach-omap2/omap_hwmod.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm/mach-omap2/omap_hwmod.c') diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c index 8fd87a3055bf..9e91a4e7519a 100644 --- a/arch/arm/mach-omap2/omap_hwmod.c +++ b/arch/arm/mach-omap2/omap_hwmod.c @@ -2065,7 +2065,7 @@ static void _reconfigure_io_chain(void) spin_lock_irqsave(&io_chain_lock, flags); - if (cpu_is_omap34xx() && omap3_has_io_chain_ctrl()) + if (cpu_is_omap34xx()) omap3xxx_prm_reconfigure_io_chain(); else if (cpu_is_omap44xx()) omap44xx_prm_reconfigure_io_chain(); -- cgit v1.2.3