From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
To: gregkh@linuxfoundation.org
Cc: mhi@lists.linux.dev, hemantk@codeaurora.org,
bbhatt@codeaurora.org, loic.poulain@linaro.org,
linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
ath11k@lists.infradead.org, linux-wireless@vger.kernel.org,
kvalo@codeaurora.org, stable@vger.kernel.org,
Pengyu Ma <mapengyu@gmail.com>,
Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Subject: [PATCH v2] bus: mhi: core: Add support for forced PM resume
Date: Thu, 9 Dec 2021 18:46:33 +0530 [thread overview]
Message-ID: <20211209131633.4168-1-manivannan.sadhasivam@linaro.org> (raw)
From: Loic Poulain <loic.poulain@linaro.org>
For whatever reason, some devices like QCA6390, WCN6855 using ath11k
are not in M3 state during PM resume, but still functional. The
mhi_pm_resume should then not fail in those cases, and let the higher
level device specific stack continue resuming process.
Add an API mhi_pm_resume_force(), to force resuming irrespective of the
current MHI state. This fixes a regression with non functional ath11k WiFi
after suspend/resume cycle on some machines.
Bug report: https://bugzilla.kernel.org/show_bug.cgi?id=214179
Fixes: 020d3b26c07a ("bus: mhi: Early MHI resume failure in non M3 state")
Cc: stable@vger.kernel.org #5.13
Link: https://lore.kernel.org/regressions/871r5p0x2u.fsf@codeaurora.org/
Reported-by: Kalle Valo <kvalo@codeaurora.org>
Reported-by: Pengyu Ma <mapengyu@gmail.com>
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
[mani: Switched to API, added bug report, reported-by tags and CCed stable]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
Changes in v2:
* Switched to a new API "mhi_pm_resume_force()" instead of the "force" flag as
suggested by Greg. The "force" flag is now used inside the API.
Greg: I'm sending this patch directly to you so that you can apply it to
char-misc once we get an ACK from Kalle.
drivers/bus/mhi/core/pm.c | 21 ++++++++++++++++++---
drivers/net/wireless/ath/ath11k/mhi.c | 6 +++++-
include/linux/mhi.h | 13 +++++++++++++
3 files changed, 36 insertions(+), 4 deletions(-)
diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
index fb99e3727155..547e6e769546 100644
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -881,7 +881,7 @@ int mhi_pm_suspend(struct mhi_controller *mhi_cntrl)
}
EXPORT_SYMBOL_GPL(mhi_pm_suspend);
-int mhi_pm_resume(struct mhi_controller *mhi_cntrl)
+static int __mhi_pm_resume(struct mhi_controller *mhi_cntrl, bool force)
{
struct mhi_chan *itr, *tmp;
struct device *dev = &mhi_cntrl->mhi_dev->dev;
@@ -898,8 +898,12 @@ int mhi_pm_resume(struct mhi_controller *mhi_cntrl)
if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state))
return -EIO;
- if (mhi_get_mhi_state(mhi_cntrl) != MHI_STATE_M3)
- return -EINVAL;
+ if (mhi_get_mhi_state(mhi_cntrl) != MHI_STATE_M3) {
+ dev_warn(dev, "Resuming from non M3 state (%s)\n",
+ TO_MHI_STATE_STR(mhi_get_mhi_state(mhi_cntrl)));
+ if (!force)
+ return -EINVAL;
+ }
/* Notify clients about exiting LPM */
list_for_each_entry_safe(itr, tmp, &mhi_cntrl->lpm_chans, node) {
@@ -940,8 +944,19 @@ int mhi_pm_resume(struct mhi_controller *mhi_cntrl)
return 0;
}
+
+int mhi_pm_resume(struct mhi_controller *mhi_cntrl)
+{
+ return __mhi_pm_resume(mhi_cntrl, false);
+}
EXPORT_SYMBOL_GPL(mhi_pm_resume);
+int mhi_pm_resume_force(struct mhi_controller *mhi_cntrl)
+{
+ return __mhi_pm_resume(mhi_cntrl, true);
+}
+EXPORT_SYMBOL_GPL(mhi_pm_resume_force);
+
int __mhi_device_get_sync(struct mhi_controller *mhi_cntrl)
{
int ret;
diff --git a/drivers/net/wireless/ath/ath11k/mhi.c b/drivers/net/wireless/ath/ath11k/mhi.c
index 26c7ae242db6..49c0b1ad40a0 100644
--- a/drivers/net/wireless/ath/ath11k/mhi.c
+++ b/drivers/net/wireless/ath/ath11k/mhi.c
@@ -533,7 +533,11 @@ static int ath11k_mhi_set_state(struct ath11k_pci *ab_pci,
ret = mhi_pm_suspend(ab_pci->mhi_ctrl);
break;
case ATH11K_MHI_RESUME:
- ret = mhi_pm_resume(ab_pci->mhi_ctrl);
+ /* Do force MHI resume as some devices like QCA6390, WCN6855
+ * are not in M3 state but they are functional. So just ignore
+ * the MHI state while resuming.
+ */
+ ret = mhi_pm_resume_force(ab_pci->mhi_ctrl);
break;
case ATH11K_MHI_TRIGGER_RDDM:
ret = mhi_force_rddm_mode(ab_pci->mhi_ctrl);
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index 723985879035..a5cc4cdf9cc8 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -663,6 +663,19 @@ int mhi_pm_suspend(struct mhi_controller *mhi_cntrl);
*/
int mhi_pm_resume(struct mhi_controller *mhi_cntrl);
+/**
+ * mhi_pm_resume_force - Force resume MHI from suspended state
+ * @mhi_cntrl: MHI controller
+ *
+ * Resume the device irrespective of its MHI state. As per the MHI spec, devices
+ * has to be in M3 state during resume. But some devices seem to be in a
+ * different MHI state other than M3 but they continue working fine if allowed.
+ * This API is intented to be used for such devices.
+ *
+ * Return: 0 if the resume succeeds, a negative error code otherwise
+ */
+int mhi_pm_resume_force(struct mhi_controller *mhi_cntrl);
+
/**
* mhi_download_rddm_image - Download ramdump image from device for
* debugging purpose.
--
2.25.1
next reply other threads:[~2021-12-09 13:16 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-09 13:16 Manivannan Sadhasivam [this message]
2021-12-09 14:35 ` [PATCH v2] bus: mhi: core: Add support for forced PM resume Kalle Valo
2021-12-09 14:42 ` Manivannan Sadhasivam
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 \
--in-reply-to=20211209131633.4168-1-manivannan.sadhasivam@linaro.org \
--to=manivannan.sadhasivam@linaro.org \
--cc=ath11k@lists.infradead.org \
--cc=bbhatt@codeaurora.org \
--cc=gregkh@linuxfoundation.org \
--cc=hemantk@codeaurora.org \
--cc=kvalo@codeaurora.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-wireless@vger.kernel.org \
--cc=loic.poulain@linaro.org \
--cc=mapengyu@gmail.com \
--cc=mhi@lists.linux.dev \
--cc=stable@vger.kernel.org \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
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).