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authorDaniel Drake <drake@endlessm.com>2017-12-12 10:49:02 +0000
committerUlf Hansson <ulf.hansson@linaro.org>2017-12-18 13:56:59 +0100
commitde8dcc3d2c0e08e5068ee1e26fc46415c15e3637 (patch)
tree4079557491ff46b3e7f4a6264663d1738c81133c /drivers/mmc/core
parentb4fcb5e5094b5f13e5c9aadea82cdbd1a4f0dd02 (diff)
mmc: avoid removing non-removable hosts during suspend
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> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc/core')
-rw-r--r--drivers/mmc/core/core.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index fd64e6d425e5..c0ba6d8823b7 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2761,6 +2761,14 @@ 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);

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