[Freedreno] PSA: ifc6410 / upstream kernel / clock status stuck at 'off' issues

[Rob Clark]

On Thu, Nov 6, 2014 at 3:09 PM, Jordan Crouse <jcrouse at codeaurora.org> wrote:
> On 11/06/2014 10:58 AM, Rob Clark wrote:
>>
>> Just FYI, newer ifc6410 boards which are shipping with android 4.4
>> bootloaders, seem to have an issue with upstream kernel.
>>
>> If you are seeing problems like:
>>
>> -------
>> [    2.472644] WARNING: CPU: 3 PID: 51 at
>> drivers/clk/qcom/clk-branch.c:97 clk_branch_wait+0xd0/0x120()
>> [    2.472659] mdp_clk status stuck at 'off'
>> [    2.472667] Modules linked in:
>> [    2.472688] CPU: 3 PID: 51 Comm: kworker/u8:1 Not tainted 3.18.0-rc1
>> #912
>> [    2.472719] Workqueue: deferwq deferred_probe_work_func
>> [    2.472784] [<c02160fc>] (unwind_backtrace) from [<c0211afc>]
>> (show_stack+0x10/0x14)
>> [    2.472824] [<c0211afc>] (show_stack) from [<c0909864>]
>> (dump_stack+0x88/0x98)
>> [    2.472859] [<c0909864>] (dump_stack) from [<c0249fa4>]
>> (warn_slowpath_common+0x6c/0x88)
>> [    2.472889] [<c0249fa4>] (warn_slowpath_common) from [<c0249ff0>]
>> (warn_slowpath_fmt+0x30/0x40)
>> [    2.472917] [<c0249ff0>] (warn_slowpath_fmt) from [<c0792964>]
>> (clk_branch_wait+0xd0/0x120)
>> [    2.472952] [<c0792964>] (clk_branch_wait) from [<c0787f78>]
>> (__clk_enable+0x5c/0x9c)
>> [    2.472975] [<c0787f78>] (__clk_enable) from [<c0788464>]
>> (clk_enable+0x18/0x2c)
>> [    2.473013] [<c0788464>] (clk_enable) from [<c054121c>]
>> (mdp4_enable+0xe4/0x110)
>> [    2.473048] [<c054121c>] (mdp4_enable) from [<c0541270>]
>> (mdp4_hw_init+0x28/0x344)
>> [    2.473075] [<c0541270>] (mdp4_hw_init) from [<c0547e60>]
>> (msm_load+0x1c8/0x34c)
>> [    2.473108] [<c0547e60>] (msm_load) from [<c052596c>]
>> (drm_dev_register+0xa8/0x104)
>> [    2.473136] [<c052596c>] (drm_dev_register) from [<c0527824>]
>> (drm_platform_init+0x44/0xdc)
>> [    2.473166] [<c0527824>] (drm_platform_init) from [<c0566538>]
>> (try_to_bring_up_master.part.3+0xc8/0x108)
>> [    2.473190] [<c0566538>] (try_to_bring_up_master.part.3) from
>> [<c0566620>] (component_master_add_with_match+0xa8/0x120)
>> -------
>>
>> Then the solution for now is to downgrade to version 4.2 rpm fw:
>>
>>     fastboot flash rpm rpm.mbn
>>
>> with rpm.mbn from Bootloaders_4.2_880261_V1.0.zip on inforce techweb site.
>>
>> I've no idea what the root cause is, or why we don't see this on the
>> downstream kernel (but I guess it is easier for someone with docs to
>> debug).  But sooner or later others will hit the same issue so I
>> figured I should send this known workaround to an archived mailing
>> list so someone googling for the error has some chance to find it ;-)
>
>
> Just so you know what is happening here this interesting combination
> of error messages is a roundabout way of telling you that you tried
> to enable a clock while the regulator was off.

right.. on the 3.4 downstream kernel, there is enough ifdeffery and
conditional compile that I'm not entirely sure how the regulators are
controlled.  But on upstream kernel they are controlled via rpm.  So I
guess that is the rpm fw <-> regulator connection.

BR,
-R

> Jordan
> --
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