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Subject[PATCH 3.18 40/47] mmc: avoid removing non-removable hosts during suspend
3.18-stable review patch.  If anyone has any objections, please let me know.


From: Daniel Drake <>

[ Upstream commit de8dcc3d2c0e08e5068ee1e26fc46415c15e3637 ]

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

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 <>
Signed-off-by: Ulf Hansson <>
Signed-off-by: Sasha Levin <>
Signed-off-by: Greg Kroah-Hartman <>
drivers/mmc/core/core.c | 8 ++++++++
1 file changed, 8 insertions(+)

--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2656,6 +2656,14 @@ int mmc_pm_notify(struct notifier_block
if (!err)

+ 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 */

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