linux-kernel - [PATCH v2 14/26] mmc: panic write: bypass bus ref locking

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Message-Id: <1352379984-18381-15-git-send-email-dragos.tatulea@intel.com>
Date:	Thu,  8 Nov 2012 15:06:12 +0200
From:	dragos.tatulea@...el.com
To:	linux-kernel@...r.kernel.org, linux-mmc@...r.kernel.org,
	cjb@...top.org
Cc:	kirill.shutemov@...ux.intel.com, irina.tirdea@...el.com,
	octavian.purdila@...el.com, tony.luck@...el.com,
	keescook@...omium.org, dragos.tatulea@...il.com,
	Adrian Hunter <adrian.hunter@...el.com>
Subject: [PATCH v2 14/26] mmc: panic write: bypass bus ref locking

From: Adrian Hunter <adrian.hunter@...el.com>

We want to avoid it while panic dumping.

Signed-off-by: Adrian Hunter <adrian.hunter@...el.com>
Signed-off-by: Irina Tirdea <irina.tirdea@...el.com>
---
 drivers/mmc/core/core.c |   10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 4fd7061..3daec19 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1418,6 +1418,11 @@ static inline void mmc_bus_get(struct mmc_host *host)
 {
 	unsigned long flags;
 
+	if (mmc_am_panic_task(host)) {
+		host->bus_refs++;
+		return;
+	}
+
 	spin_lock_irqsave(&host->lock, flags);
 	host->bus_refs++;
 	spin_unlock_irqrestore(&host->lock, flags);
@@ -1431,6 +1436,11 @@ static inline void mmc_bus_put(struct mmc_host *host)
 {
 	unsigned long flags;
 
+	if (mmc_am_panic_task(host)) {
+		host->bus_refs--;
+		return;
+	}
+
 	spin_lock_irqsave(&host->lock, flags);
 	host->bus_refs--;
 	if ((host->bus_refs == 0) && host->bus_ops)
-- 
1.7.9.5

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