Re: [PATCH 0/3] omap: hwmod: add default reset handling support

[Dave Gerlach]

Hi,
On 02/09/2016 11:44 AM, Suman Anna wrote:
> On 02/08/2016 11:17 PM, Kishon Vijay Abraham I wrote:
> > Hi,
> >
> > On Tuesday 09 February 2016 02:37 AM, Suman Anna wrote:
> > > On 02/08/2016 05:12 AM, Kishon Vijay Abraham I wrote:
> > > > Add a new hwmod flag to indicate custom reset handling and use it
> > > > for devices that require custom reset handling (like dsp, ipu, iva).
> > > >
> > > > Tested PCIe on dra7-evm and dra72-evm.
> > > > I need help in testing DSP, IPU, IVA, PRU, GFX, M3 in other platforms.
> > > > Or a way to test these cores to see if reset is not broken. Suman?
> > >
> > > I won't be able to test this week, and have requested Dave to check on
> > > wkup_m3_rproc driver atleast. I see one potential issue (see my commment
> > > on the other thread), but can confirm that only after testing.
> > >
> > > Have you tested multiple probe/removal sequences? Can you check the
> > > return status on the _hardreset_deassert call with your PCIe driver,
> > > believe even that one would return an error on multiple probes.
> >
> > hmm.. the PCIe driver is built-in and can't be made as module because of other
> > issues in PCIe core. But looks like the first deassert succeeded since I didn't
> > observe the boot hang because of PCIe.
>
> You can try unbind and bind through sysfs, it should result in a remove
> and probe even if your driver is built-in.

Sorry got held up by the discussion here [1], that regression affects 
rmmod/re-insmod of wkup_m3_rproc as well. If I revert the guilty patch 
5de85b9d57ab ("PM / runtime: Re-init runtime
PM states at probe error and driver unbind") and apply these three 
patches, on initial probe of the wkup_m3_rproc and wkup_m3_ipc drivers 
in v4.5-rc3 I see:

[   15.593460] omap_hwmod: wkup_m3: _wait_target_disable failed

Which is triggered by the reset of the wkup_m3 from the wkup_m3_ipc 
driver when booting the wkup_m3_rproc. Flow is:

1. wkup_m3_rproc probes and calls pm_runtime_get_sync, which calls hwmod 
_enable but bails out because _are_all_hardreset_lines_asserted(oh) 
causes it to return 0.

2. wkup_m3_ipc probes and calls rproc_boot, which triggers 
omap_device_deassert_hardreset in order to let the wkup_m3 start.

It is inside the omap_device_deassert_hardreset ( and inside that, 
omap_hwmod_deassert_hardreset) where I end up with the error message, 
but after that rmmod/insmod of the module over and over again shows no 
additional error messages (at least with the above mentioned PM patch 
reverted).

Regards,
Dave

[1] http://www.spinics.net/lists/arm-kernel/msg477160.html

> regards
> Suman
> > > > I'll post this series once again after performing these tests.
> > > >
> > > > Paul Walmsley (3):
> > > >    ARM: omap2+: omap_hwmod: introduce hwmod flag for custom reset
> > > >      handling
> > > >    ARM: OMAP2+: hwmod: use HWMOD_CUSTOM_HARDRESET for custom reset
> > > >      handling
> > > >    ARM: OMAP2+: hwmod: Add default reset handling
> > > >
> > > >   arch/arm/mach-omap2/omap_hwmod.c                   |   16 +++++++++++-----
> > > >   arch/arm/mach-omap2/omap_hwmod.h                   |   12 ++++++++++++
> > > >   arch/arm/mach-omap2/omap_hwmod_2420_data.c         |    2 ++
> > > >   arch/arm/mach-omap2/omap_hwmod_2430_data.c         |    1 +
> > > >   .../mach-omap2/omap_hwmod_33xx_43xx_ipblock_data.c |    2 ++
> > > >   arch/arm/mach-omap2/omap_hwmod_33xx_data.c         |    1 +
> > > >   arch/arm/mach-omap2/omap_hwmod_3xxx_data.c         |    3 +++
> > > >   arch/arm/mach-omap2/omap_hwmod_43xx_data.c         |    1 +
> > > >   arch/arm/mach-omap2/omap_hwmod_44xx_data.c         |    6 ++++++
> > > >   arch/arm/mach-omap2/omap_hwmod_54xx_data.c         |    2 ++
> > > >   10 files changed, 41 insertions(+), 5 deletions(-)