Re: [PATCH] ARM: OMAP2+: hwmod: Fix _wait_target_ready() for hwmods without sysc
From: Suman Anna
Date: Tue Jan 06 2015 - 12:27:59 EST
Hi Paul,
On 01/06/2015 11:14 AM, Suman Anna wrote:
> Hi Paul,
>
> On 01/06/2015 02:14 AM, Lokesh Vutla wrote:
>> Hi Paul,
>> On Tuesday 06 January 2015 07:34 AM, Paul Walmsley wrote:
>>>
>>> Roger, Lokesh, could you try this one instead?
>> Yep, the below patch works on AM437x.
>> Boot logs here: http://paste.ubuntu.com/9680938/
>>
>> Thanks and regards,
>> Lokesh
>>>
>>> It passes all the basic tests here except it does not boot on the 4460
>>> VAR-SOM-OM - unclear why at this point - but it would be good to see if it
>>> works on your AM4372 boards, since I don't have that one.
Looking at your rc3 log @
http://www.pwsan.com/omap/testlogs/test_v3.19-rc3/20150105224749/boot/4460varsomom/,
I do see a missing reg entry for mailbox, and that's the reason for your
hang because of the missing bail out in your new patch.
[ 0.261932] ------------[ cut here ]------------
[ 0.261962] WARNING: CPU: 0 PID: 1 at
arch/arm/mach-omap2/omap_hwmod.c:2458 _init+0x3a0/0x3f0()
[ 0.261962] omap_hwmod: mailbox: doesn't have mpu register target base
...
...
[ 0.262329] ---[ end trace a1be72591db4662e ]---
Now that said, this is weird, since the reg property for mailbox is
defined in the base omap4.dtsi and should be inherited by the 4460
VAR-SOM-OM, unless you are booting with an old dtb.
regards
Suman
>>>
>>> Test logs are here:
>>>
>>> http://www.pwsan.com/omap/testlogs/hwmod_skip_only_remap_v3.19-rc/20150105171744/
>>>
>>>
>>> - Paul
>>>
>>>
>>> From 4f2e13bd2181e0ebede3aabc484aa2339830748a Mon Sep 17 00:00:00 2001
>>> From: Paul Walmsley <paul@xxxxxxxxx>
>>> Date: Mon, 5 Jan 2015 15:49:57 -0700
>>> Subject: [PATCH] Only skip ioremap() if IP block does not have OCP header
>>> registers. Experimental.
>>>
>>> ---
>>> arch/arm/mach-omap2/omap_hwmod.c | 33 +++++++++++++++++++++------------
>>> 1 file changed, 21 insertions(+), 12 deletions(-)
>>>
>>> diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
>>> index cbb908dc5cf0..03df8833d399 100644
>>> --- a/arch/arm/mach-omap2/omap_hwmod.c
>>> +++ b/arch/arm/mach-omap2/omap_hwmod.c
>>> @@ -1938,6 +1938,8 @@ static int _reset(struct omap_hwmod *oh)
>>> pr_debug("omap_hwmod: %s: resetting\n", oh->name);
>>>
>>> if (oh->class->reset) {
>>> + WARN(!oh->_mpu_rt_va, "Attempt to call custom reset with no MPU register target ioremapped: %s",
>>> + oh->name);
>>> r = oh->class->reset(oh);
>>> } else {
>>> if (oh->rst_lines_cnt > 0) {
>>> @@ -2358,15 +2360,19 @@ static int of_dev_hwmod_lookup(struct device_node *np,
>>> }
>>>
>>> /**
>>> - * _init_mpu_rt_base - populate the virtual address for a hwmod
>>> + * _init_mpu_rt_base - populate the MPU port and virtual address
>>> * @oh: struct omap_hwmod * to locate the virtual address
>>> * @data: (unused, caller should pass NULL)
>>> * @index: index of the reg entry iospace in device tree
>>> * @np: struct device_node * of the IP block's device node in the DT data
>>> *
>>> - * Cache the virtual address used by the MPU to access this IP block's
>>> - * registers. This address is needed early so the OCP registers that
>>> - * are part of the device's address space can be ioremapped properly.
>>> + * Cache the interconnect target port and the virtual address used by
>>> + * the MPU to access this IP block's registers. The address is needed
>>> + * early so the OCP registers that are part of the device's address
>>> + * space can be ioremapped properly. The presence or absence of the
>>> + * interconnect target port also indicates whether the hwmod code
>>> + * should wait for the IP block to indicate readiness after it is
>>> + * enabled.
>>> *
>>> * Returns 0 on success, -EINVAL if an invalid hwmod is passed, and
>>> * -ENXIO on absent or invalid register target address space.
>>> @@ -2385,6 +2391,13 @@ static int __init _init_mpu_rt_base(struct omap_hwmod *oh, void *data,
>>> if (oh->_int_flags & _HWMOD_NO_MPU_PORT)
>>> return -ENXIO;
>>>
>>> + /*
>>> + * If there's no need for the hwmod code to read or write to
>>> + * the IP block registers, bail out early before the ioremap()
>>> + */
>>> + if (!oh->class->sysc)
>>> + return 0;
>>> +
>>> mem = _find_mpu_rt_addr_space(oh);
>>> if (!mem) {
>>> pr_debug("omap_hwmod: %s: no MPU register target found\n",
>>> @@ -2451,14 +2464,10 @@ static int __init _init(struct omap_hwmod *oh, void *data)
>>> oh->name, np->name);
>>> }
>>>
>>> - if (oh->class->sysc) {
>>> - r = _init_mpu_rt_base(oh, NULL, index, np);
>>> - if (r < 0) {
>>> - WARN(1, "omap_hwmod: %s: doesn't have mpu register target base\n",
>>> - oh->name);
>>> - return 0;
>>> - }
>>> - }
>>> + r = _init_mpu_rt_base(oh, NULL, index, np);
>>> + if (r < 0)
>>> + pr_debug("omap_hwmod: %s: doesn't have mpu register target base\n",
>>> + oh->name);
>
> You have removed the return from the above block on failure. If any DT
> entry doesn't have the reg property, this will hang the kernel boot.
> Just remove the "reg" entry from any of the existing DT, and you will
> run into the issue, this is what 6423d6df1440 ("ARM: OMAP2+: hwmod:
> check for module address space during init") fixed. Also, are you sure
> you want to turn the WARN into a pr_debug, it won't even show during the
> kernel boot log if the reg base is missing.
>
> regards
> Suman
>
>>>
>>> r = _init_clocks(oh, NULL);
>>> if (r < 0) {
>>>
>>
>
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