Revert "mmc: fix a race between card-detect rescan and clock-gate work instances"
This reverts commit 26fc8775b51484d8c0a671198639c6d5ae60533e, which has
been reported to cause boot/resume-time crashes for some users:
https://bbs.archlinux.org/viewtopic.php?id=118751.
Signed-off-by: Chris Ball <cjb@laptop.org>
Cc: <stable@kernel.org>
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
index 2b200c1..461e6a1 100644
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -94,7 +94,7 @@
spin_unlock_irqrestore(&host->clk_lock, flags);
return;
}
- mmc_claim_host(host);
+ mutex_lock(&host->clk_gate_mutex);
spin_lock_irqsave(&host->clk_lock, flags);
if (!host->clk_requests) {
spin_unlock_irqrestore(&host->clk_lock, flags);
@@ -104,7 +104,7 @@
pr_debug("%s: gated MCI clock\n", mmc_hostname(host));
}
spin_unlock_irqrestore(&host->clk_lock, flags);
- mmc_release_host(host);
+ mutex_unlock(&host->clk_gate_mutex);
}
/*
@@ -130,7 +130,7 @@
{
unsigned long flags;
- mmc_claim_host(host);
+ mutex_lock(&host->clk_gate_mutex);
spin_lock_irqsave(&host->clk_lock, flags);
if (host->clk_gated) {
spin_unlock_irqrestore(&host->clk_lock, flags);
@@ -140,7 +140,7 @@
}
host->clk_requests++;
spin_unlock_irqrestore(&host->clk_lock, flags);
- mmc_release_host(host);
+ mutex_unlock(&host->clk_gate_mutex);
}
/**
@@ -215,6 +215,7 @@
host->clk_gated = false;
INIT_WORK(&host->clk_gate_work, mmc_host_clk_gate_work);
spin_lock_init(&host->clk_lock);
+ mutex_init(&host->clk_gate_mutex);
}
/**
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index eb792cb..bcb793e 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -183,6 +183,7 @@
struct work_struct clk_gate_work; /* delayed clock gate */
unsigned int clk_old; /* old clock value cache */
spinlock_t clk_lock; /* lock for clk fields */
+ struct mutex clk_gate_mutex; /* mutex for clock gating */
#endif
/* host specific block data */