On Sat, 2020-10-31 at 00:27 +0900, Tsuchiya Yuto wrote: > On Wed, 2020-10-28 at 23:27 +0900, Tsuchiya Yuto wrote: >> On Microsoft Surface devices (PCIe-88W8897), there are issues with S0ix >> achievement and AP scanning after suspend with the current Host Sleep >> method. >> >> When using the Host Sleep method, it prevents the platform to reach S0ix >> during suspend. Also, sometimes AP scanning won't work, resulting in >> non-working wifi after suspend. >> >> To fix such issues, perform shutdown_sw()/reinit_sw() instead of Host >> Sleep on suspend/resume. >> >> Signed-off-by: Tsuchiya Yuto <kitakar@xxxxxxxxx> >> --- >> As a side effect, this patch disables wakeups (means that Wake-On-WLAN >> can't be used anymore, if it was working before), and might also reset >> some internal states. >> >> Of course it's the best to rather fix Host Sleep itself. But if it's >> difficult, I'm afraid we have to go this way. >> >> I reused the contents of suspend()/resume() functions as much as possible, >> and removed only the parts that are incompatible or redundant with >> shutdown_sw()/reinit_sw(). >> >> - Removed wait_for_completion() as redundant >> mwifiex_shutdown_sw() does this. >> - Removed flush_workqueue() as incompatible >> Causes kernel crashing. >> - Removed mwifiex_enable_wake()/mwifiex_disable_wake() >> as incompatible and redundant because the driver will be shut down >> instead of entering Host Sleep. >> >> I'm worried about why flush_workqueue() causes kernel crash with this >> suspend method. Is it OK to just drop it? At least We Microsoft Surface >> devices users used this method for about one month and haven't observed >> any issues. >> >> Note that suspend() no longer checks if it's already suspended. >> With the previous Host Sleep method, the check was done by looking at >> adapter->hs_activated in mwifiex_enable_hs() [sta_ioctl.c], but not >> MWIFIEX_IS_SUSPENDED. So, what the previous method checked was instead >> Host Sleep state, not suspend itself. >> >> Therefore, there is no need to check the suspend state now. >> Also removed comment for suspend state check at top of suspend() >> accordingly. > > This patch depends on the following mwifiex_shutdown_sw() fix I sent > separately. > > [PATCH 1/2] mwifiex: fix mwifiex_shutdown_sw() causing sw reset failure > https://lore.kernel.org/linux-wireless/20201028142110.18144-2-kitakar@xxxxxxxxx/ The AP scanning issue with Host Sleep is now difficult to reproduce on v5.10-rc2. It might be already gone but not yet so sure. Here are the details about AP scanning issue with Host Sleep for the record (as of Apr 2020): When using Host Sleep on suspend, after resuming from suspend, it (sometimes) can't connect to APs because it fails to scan APs. When I set debug_mask to 0xffffffff, I noticed that scanning is being blocked with this message: kern :info : [99952.621609] mwifiex_pcie 0000:03:00.0: info: received scan request on mlan0 kern :info : [99952.621613] mwifiex_pcie 0000:03:00.0: cmd: Scan already in process.. What is worse, when this issue happened, the subsequent suspend (sometimes) fails with the following message: kern :info : [101844.423427] mwifiex_pcie 0000:03:00.0: hs_activate_wait_q terminated kern :info : [101844.423433] mwifiex_pcie 0000:03:00.0: cmd: failed to suspend kern :err : [101844.423446] PM: pci_pm_suspend(): mwifiex_pcie_suspend+0x0/0xd0 [mwifiex_pcie] returns -14 kern :err : [101844.423453] PM: dpm_run_callback(): pci_pm_suspend+0x0/0x160 returns -14 kern :err : [101844.423466] PM: Device 0000:03:00.0 failed to suspend async: error -14 kern :debug : [101844.423525] PM: suspend of devices aborted after 10064.914 msecs kern :debug : [101844.423529] PM: start suspend of devices aborted after 10065.318 msecs kern :err : [101844.423531] PM: Some devices failed to suspend, or early wake event detected The message is from the following code in mwifiex_cfg80211_scan() [cfg80211.c]. /* Block scan request if scan operation or scan cleanup when interface * is disabled is in process */ if (priv->scan_request || priv->scan_aborting) { mwifiex_dbg(priv->adapter, WARN, "cmd: Scan already in process..\n"); return -EBUSY; } Further print debugging showed that scan_request was not true but scan_aborting was true. And the scan_aborting was set by mwifiex_close() [main.c]. Regarding the S0ix achievement, I don't have any idea how I can fix it with the Host Sleep method. So, I sent this patch. Any suggestions for fixing it with Host Sleep are welcome. If I understand correctly, the mwifiex card is in fully working state in terms of PCIe. This prevents the platform from going into S0ix state? >> drivers/net/wireless/marvell/mwifiex/pcie.c | 29 +++++++-------------- >> 1 file changed, 10 insertions(+), 19 deletions(-) >> >> diff --git a/drivers/net/wireless/marvell/mwifiex/pcie.c b/drivers/net/wireless/marvell/mwifiex/pcie.c >> index 6a10ff0377a24..3b5c614def2f5 100644 >> --- a/drivers/net/wireless/marvell/mwifiex/pcie.c >> +++ b/drivers/net/wireless/marvell/mwifiex/pcie.c >> @@ -293,8 +293,7 @@ static bool mwifiex_pcie_ok_to_access_hw(struct mwifiex_adapter *adapter) >> * registered functions must have drivers with suspend and resume >> * methods. Failing that the kernel simply removes the whole card. >> * >> - * If already not suspended, this function allocates and sends a host >> - * sleep activate request to the firmware and turns off the traffic. >> + * This function shuts down the adapter. >> */ >> static int mwifiex_pcie_suspend(struct device *dev) >> { >> @@ -302,31 +301,21 @@ static int mwifiex_pcie_suspend(struct device *dev) >> struct pcie_service_card *card = dev_get_drvdata(dev); >> >> >> - /* Might still be loading firmware */ >> - wait_for_completion(&card->fw_done); >> - >> adapter = card->adapter; >> if (!adapter) { >> dev_err(dev, "adapter is not valid\n"); >> return 0; >> } >> >> - mwifiex_enable_wake(adapter); >> - >> - /* Enable the Host Sleep */ >> - if (!mwifiex_enable_hs(adapter)) { >> + /* Shut down SW */ >> + if (mwifiex_shutdown_sw(adapter)) { >> mwifiex_dbg(adapter, ERROR, >> "cmd: failed to suspend\n"); >> - clear_bit(MWIFIEX_IS_HS_ENABLING, &adapter->work_flags); >> - mwifiex_disable_wake(adapter); >> return -EFAULT; >> } >> >> - flush_workqueue(adapter->workqueue); >> - >> /* Indicate device suspended */ >> set_bit(MWIFIEX_IS_SUSPENDED, &adapter->work_flags); >> - clear_bit(MWIFIEX_IS_HS_ENABLING, &adapter->work_flags); >> >> return 0; >> } >> @@ -336,13 +325,13 @@ static int mwifiex_pcie_suspend(struct device *dev) >> * registered functions must have drivers with suspend and resume >> * methods. Failing that the kernel simply removes the whole card. >> * >> - * If already not resumed, this function turns on the traffic and >> - * sends a host sleep cancel request to the firmware. >> + * If already not resumed, this function reinits the adapter. >> */ >> static int mwifiex_pcie_resume(struct device *dev) >> { >> struct mwifiex_adapter *adapter; >> struct pcie_service_card *card = dev_get_drvdata(dev); >> + int ret; >> >> >> if (!card->adapter) { >> @@ -360,9 +349,11 @@ static int mwifiex_pcie_resume(struct device *dev) >> >> clear_bit(MWIFIEX_IS_SUSPENDED, &adapter->work_flags); >> >> - mwifiex_cancel_hs(mwifiex_get_priv(adapter, MWIFIEX_BSS_ROLE_STA), >> - MWIFIEX_ASYNC_CMD); >> - mwifiex_disable_wake(adapter); >> + ret = mwifiex_reinit_sw(adapter); >> + if (ret) >> + dev_err(dev, "reinit failed: %d\n", ret); >> + else >> + mwifiex_dbg(adapter, INFO, "%s, successful\n", __func__); >> >> return 0; >> } > >
