From: Carl Huang <firstname.lastname@example.org> To: Manivannan Sadhasivam <email@example.com> Cc: Kalle Valo <firstname.lastname@example.org>, Loic Poulain <email@example.com>, firstname.lastname@example.org, linux-arm-msm <email@example.com>, firstname.lastname@example.org, email@example.com Subject: Re: [regression] mhi: ath11k resume fails on some devices Date: Thu, 23 Sep 2021 17:26:56 +0800 [thread overview] Message-ID: <firstname.lastname@example.org> (raw) In-Reply-To: <20210923085926.GD6083@thinkpad> On 2021-09-23 16:59, Manivannan Sadhasivam wrote: > On Thu, Sep 23, 2021 at 04:34:43PM +0800, Carl Huang wrote: >> On 2021-09-17 01:19, Manivannan Sadhasivam wrote: >> > On Thu, Sep 16, 2021 at 07:42:02PM +0300, Kalle Valo wrote: >> > > Manivannan Sadhasivam <email@example.com> writes: >> > > >> > > > On Thu, Sep 16, 2021 at 01:18:22PM +0200, Loic Poulain wrote: >> > > >> Le jeu. 16 sept. 2021 à 13:12, Manivannan Sadhasivam < >> > > >> firstname.lastname@example.org> a écrit : >> > > >> >> > > > >> > > > [...] >> > > > >> > > >> > If things seems to work fine without that patch, then it implies that >> > > >> > setting M0 >> > > >> > state works during resume. I think we should just revert that patch. >> > > >> > >> > > >> > Loic, did that patch fix any issue for you or it was a cosmetic fix only? >> > > >> >> > > >> >> > > >> It fixes sdx modem resuming issue, without that we don’t know modem needs >> > > >> to be reinitialized. >> > > >> >> > > > >> > > > Okay. Then in that case, the recovery mechanism has to be added to the ath11k >> > > > MHI controller. >> > > >> > > What does that mean in practise, do you have any pointers or >> > > examples? I >> > > have no clue what you are proposing :) >> > > >> > >> > Take a look at the mhi_pci_recovery_work() function below: >> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/bus/mhi/pci_generic.c#n610 >> > >> > You need to implement something similar that basically powers up the MHI >> > endpoint (QCA6390) in case pm_resume() fails. At minimum, you need to >> > call >> > below functions: >> > >> > # Check if the device is powered on. If yes, then power it down to bring >> > it back >> > mhi_power_down() >> > mhi_unprepare_after_power_down() >> > >> > # Power up the device >> > mhi_prepare_for_power_up() >> > mhi_sync_power_up() >> > >> > This implies that the WLAN device has been powered off during suspend, >> > so the >> > resume fails and we are bringing the device back to working state. >> > >> This is fine for platform which doesn't provide power supply during >> suspend. >> But NUC has power supply in suspend state. > > If NUC retains power supply during suspend then it should work with > that commit. > During resume, the device is expected to be in M3 state and that's what > the > commit verifies. > > If the device is in a different state, then most likely the device have > power > cycled. > But the tricky thing here is that upstream QCA6390 doesn't have recovery mechanism to download firmware again, so QCA6390 has no way to work after a power cycle. >> QCA6390 on NUC works after just reverting this commit also proves NUC >> has >> power supply in >> suspend state. >> > > That's because we allowed the device to be in any state during resume > and if it > responds to the M0 transition it worked. > >> The reason is MHI-STATUS register can't be read somehow in M3 state on >> NUC. > > No, that's not correct. > >> Does the MHI spec state that MHI-STATUS register can be read in M3 >> state? >> > > Yes, all the MHI registers are accessible in all states. During M3, > both MHI > host and device (if supported) will transition to D3 Cold. Then during > resume, > host will switch to D0 link state and will also notify the device to > enter D0. > > For aid debugging, please see the state the device is in during > mhi_pm_resume(). > You can use below diff: > > diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c > index fb99e3727155..482d55dd209e 100644 > --- a/drivers/bus/mhi/core/pm.c > +++ b/drivers/bus/mhi/core/pm.c > @@ -898,6 +898,9 @@ int mhi_pm_resume(struct mhi_controller *mhi_cntrl) > if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) > return -EIO; > > + dev_info(dev, "Device state: %s\n", > + TO_MHI_STATE_STR(mhi_get_mhi_state(mhi_cntrl))); > + > if (mhi_get_mhi_state(mhi_cntrl) != MHI_STATE_M3) > return -EINVAL; > > > Thanks, > Mani
next prev parent reply other threads:[~2021-09-23 9:26 UTC|newest] Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-09-16 8:00 Kalle Valo 2021-09-16 10:18 ` Loic Poulain 2021-09-16 11:12 ` Manivannan Sadhasivam [not found] ` <CAMZdPi94607mZorp+Zmkw3seWXak6p9Jr05CQ5hhfgKQoG8n7Q@mail.gmail.com> 2021-09-16 16:35 ` Manivannan Sadhasivam 2021-09-16 16:42 ` Kalle Valo 2021-09-16 17:19 ` Manivannan Sadhasivam 2021-09-23 8:34 ` Carl Huang 2021-09-23 8:59 ` Manivannan Sadhasivam 2021-09-23 9:26 ` Carl Huang [this message] 2021-09-23 10:50 ` Loic Poulain 2021-09-24 9:07 ` Kalle Valo 2021-09-24 9:57 ` Manivannan Sadhasivam 2021-10-07 9:55 ` Kalle Valo 2021-10-21 10:01 ` Manivannan Sadhasivam 2021-09-24 8:36 ` Kalle Valo 2021-09-24 9:43 ` Loic Poulain 2021-09-24 10:00 ` Manivannan Sadhasivam 2021-10-07 9:48 ` Kalle Valo 2021-10-19 12:12 ` Kalle Valo 2021-10-21 10:03 ` Manivannan Sadhasivam 2021-11-12 11:36 ` Thorsten Leemhuis 2021-11-18 17:41 ` Manivannan Sadhasivam 2021-12-01 7:34 ` Thorsten Leemhuis 2021-09-25 17:40 ` Thorsten Leemhuis
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --email@example.com \ --firstname.lastname@example.org \ --email@example.com \ --firstname.lastname@example.org \ --email@example.com \ --firstname.lastname@example.org \ --email@example.com \ --firstname.lastname@example.org \ --email@example.com \ --subject='Re: [regression] mhi: ath11k resume fails on some devices' \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).