From de8dcc3d2c0e08e5068ee1e26fc46415c15e3637 Mon Sep 17 00:00:00 2001 From: Daniel Drake Date: Tue, 12 Dec 2017 10:49:02 +0000 Subject: [PATCH] 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 Signed-off-by: Ulf Hansson --- drivers/mmc/core/core.c | 8 ++++++++ 1 file changed, 8 insertions(+) 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); -- GitLab