| Message ID | 20171212104902.11793-1-drake@endlessm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 12 December 2017 at 11:49, Daniel Drake <drake@endlessm.com> wrote: > The Weibu F3C MiniPC has an onboard AP6255 module, presenting > two SDIO functions on a single MMC host (Bluetooth/btsdio and > WiFi/brcmfmac), and the mmc layer correctly detects this as > non-removable. > > After suspend/resume, the wifi and bluetooth interfaces disappear > and do not get probed again. > > The conditions here are: > > 1. During suspend, we reach mmc_pm_notify() > > 2. mmc_pm_notify() calls mmc_sdio_pre_suspend() to see if we can > suspend the SDIO host. However, mmc_sdio_pre_suspend() returns > -ENOSYS because btsdio_driver does not have a suspend method. > > 3. mmc_pm_notify() proceeds to remove the card > > 4. Upon resume, mmc_rescan() does nothing with this host, because of > the rescan_entered check which aims to only scan a non-removable > device a single time (i.e. during boot). > > Fix the loss of functionality by detecting that we are unable to > suspend a non-removable host, so avoid the forced removal in that > case. The comment above this function already indicates that this > code was only intended for removable devices. > > Signed-off-by: Daniel Drake <drake@endlessm.com> Thanks, applied for next! Kind regards Uffe > --- > drivers/mmc/core/core.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > Replaces previous approach: > [PATCH] mmc: allow rescan of non-removable hosts on resume > > diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c > index 26431267a3e2..6f815a264285 100644 > --- a/drivers/mmc/core/core.c > +++ b/drivers/mmc/core/core.c > @@ -2763,6 +2763,14 @@ static int mmc_pm_notify(struct notifier_block *notify_block, > if (!err) > break; > > + if (!mmc_card_is_removable(host)) { > + dev_warn(mmc_dev(host), > + "pre_suspend failed for non-removable host: " > + "%d\n", err); > + /* Avoid removing non-removable hosts */ > + break; > + } > + > /* Calling bus_ops->remove() with a claimed host can deadlock */ > host->bus_ops->remove(host); > mmc_claim_host(host); > -- > 2.14.1 > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 26431267a3e2..6f815a264285 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -2763,6 +2763,14 @@ static int mmc_pm_notify(struct notifier_block *notify_block, if (!err) break; + if (!mmc_card_is_removable(host)) { + dev_warn(mmc_dev(host), + "pre_suspend failed for non-removable host: " + "%d\n", err); + /* Avoid removing non-removable hosts */ + break; + } + /* Calling bus_ops->remove() with a claimed host can deadlock */ host->bus_ops->remove(host); mmc_claim_host(host);
The Weibu F3C MiniPC has an onboard AP6255 module, presenting two SDIO functions on a single MMC host (Bluetooth/btsdio and WiFi/brcmfmac), and the mmc layer correctly detects this as non-removable. After suspend/resume, the wifi and bluetooth interfaces disappear and do not get probed again. The conditions here are: 1. During suspend, we reach mmc_pm_notify() 2. mmc_pm_notify() calls mmc_sdio_pre_suspend() to see if we can suspend the SDIO host. However, mmc_sdio_pre_suspend() returns -ENOSYS because btsdio_driver does not have a suspend method. 3. mmc_pm_notify() proceeds to remove the card 4. Upon resume, mmc_rescan() does nothing with this host, because of the rescan_entered check which aims to only scan a non-removable device a single time (i.e. during boot). Fix the loss of functionality by detecting that we are unable to suspend a non-removable host, so avoid the forced removal in that case. The comment above this function already indicates that this code was only intended for removable devices. Signed-off-by: Daniel Drake <drake@endlessm.com> --- drivers/mmc/core/core.c | 8 ++++++++ 1 file changed, 8 insertions(+) Replaces previous approach: [PATCH] mmc: allow rescan of non-removable hosts on resume