Re: [PATCH v4 00/21] OMAP UART Patches

From: Felipe Balbi
Date: Sat Sep 08 2012 - 15:09:04 EST


On Fri, Sep 07, 2012 at 01:53:11PM -0700, Kevin Hilman wrote:
> Felipe Balbi <balbi@xxxxxx> writes:
> > Hi,
> >
> > On Thu, Sep 06, 2012 at 03:44:13PM -0700, Kevin Hilman wrote:
> >> Felipe Balbi <balbi@xxxxxx> writes:
> >>
> >> > Hi guys,
> >> >
> >> > here's v4 of the omap uart patchset. No changes other than a rebase on top of
> >> > Greg's tty-next branch and Tony's Acked-by being added to a couple patches
> >> >
> >> > Note: I'm resending the series with Vikram's Software Flow Control fix anyway
> >> > as it can just be ignored if it's decided it needs to go into this merge
> >> > window.
> >>
> >> Sorry to be late to the party... just getting back from some time off.
> >>
> >> I'm assuming that this was not tested with PM, so decided I better do it
> >
> > you assumed wrong. See the previous versions of the series and you'll
> > see I mention all the basic pm testing I did.
> My apologies for not reading the previous versions. I don't think it's
> unusual that a reviewer should expect everything he to know about a
> series (including how it was tested) is in the cover letter or in the
> changelogs of the latest series. I don't expect to have to look through

you've got a point there. My bad, should've kept series history on all

> all the previous versions for this kind of info. Since I wasn't around
> to review/test the earlier versions, I just looked at the latest (v4)
> and didn't see any mention of testing of any sort in the cover letter.

Well, fair enough. Maybe I wasn't too verbose, but here's what I did on

. check that console still works
. check that IRQs increase as I type on console
. check that pm_runtime suspend callback is called after 1 second of
inactivity (with printk)
. check that device resumes properly when I type on console again
. enable UART wakeup (through sysfs) and 'echo mem > /sys/power/state'
then check that I can wakeup from suspend and check that all
powerdomains actually reached low power state

> Looking back at the previous cover letters, I don't see any description
> of the PM testing either. I only see it was tested on pandaboard.

Yeah, initially I wasn't testing PM because UART wakeup was known to be
broken, but then I decided to test and sent it as a reply to cover
letter v2, then I forgot to keep the history on v3 and v4. My bad.

> Since mainline doesn't have full PM support for OMAP4, testing on panda
> doesn't really test UART PM at all.

Fair enough. What's missing for omap4 panda ? I could reach suspend2ram
with echo mem > /sys/power/state and wakeup from it.

> Could you please point me to the descriptions in earlier mails of how
> you did PM testing, and on what platforms?

Though not on a cover letter, this is how I was testing from v2 and

> In addition, IMO, if this was only tested on Panda (as suggested by
> earlier cover letters), it really should not have been merged until it
> got some broader testing.

Shubhro's got his Tested-by tag. I believe he tested on beagleboard and
omap4sdp. Shubhro, can you confirm which platforms you tested the UART
patches ? cheers

> >> myself seeing that Greg is has already merge it. To test, I merged
> >> Greg's tty-next branch with v3.6-rc4 and did some PM testing.
> >>
> >> The bad news is that it doesn't even compile (see reply to [PATCH v4
> >> 20/21]).
> >
> > yeah, that was an automerge issue when rebasing on greg's tty-next
> > branch, plus me assuming omap serial was already enabled on my .config
> > and not checking the compile output. Sent a patch now.
> As I reported in my reply to [PATCH v4 20/21], that patch also had
> another problem where it introduced a new (but unused) field. Maybe
> another rebase problem? I see the same problem in v3 and v4.

I'll check it out and make sure to delete any such unused fields. Thanks

> >> Also, there is a big WARNING on boot[1], which seems to be triggered by
> >> a new check added for v3.6-rc3[2]. This appears to be introduced by
> >> $SUBJECT series, because I don't see it on vanilla v3.6-rc4.
> [...]
> > This doesn't seem to be caused by $SUBJECT at all. See that we are
> > calling uart_add_one_port() which will call tty_port_register_device()
> > which, in turn, will call tty_port_link_device() and that will set
> > driver->ports[index] correctly.
> >
> > Have you checked if this doesn't happen without my series before waving
> > your blame hammer ? FWIW, that part of the code wasn't change by
> > $SUBJECT at all.
> Whoa. This was only test report. No need to get personal. All I said
> is that it "seemed" to introduced by $SUBJECT series. Hardly waiving
> "blame hammer."

fair enough.

> And yes, I did check without your series. As I reported above, the

What about v3.6-rc4 + the patch which added the warning ? :-)

> warning didn't exist with v3.6-rc4, and it did with yesterday's tty-next
> branch. The WARNING pointed a finger at ttyO (omap-serial) so I assumed
> it was in $SUBJECT series.
> Testing with todays tty-next, the problem is gone. The patch
> 'tty_register_device_attr updated for tty-next'[1] seems to have made
> the problem go away. So it's now clear that it wasn't introduced by
> $SUBJECT series. My bad.


> Yesterday, it wasn't that obvious, so I made an assumption in order to
> report a problem uncovered in my testing in the hopes that it would be
> helpful to you in fixing a potential problem. My assumption was wrong, I
> was wrong. I'm wrong a lot, and I'm OK with that. The bug was
> elsewhere, and is already fixed.
> My apologies if it seemed like I was blaming you.

I'm the one who owes you an apology for misunderstanding your bug
report. I'm sorry.


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