Re: [PATCH V2] mmc: Kill block requests if card is removed

[Adrian Hunter <adrian.hunter@intel.com>]

Hi

Here is a way to allow mmc block to determine immediately
if a card has been removed while preserving the present rules
and keeping card detection in the bus_ops.

Untested I'm afraid.

Regards
Adrian



>From 2c6c9535b94c07fa3d12af26e9b6de500cb29970 Mon Sep 17 00:00:00 2001
From: Adrian Hunter <adrian.hunter@intel.com>
Date: Thu, 24 Nov 2011 16:32:34 +0200
Subject: [PATCH] mmc: allow upper layers to determine immediately if a card has been removed

Add a function mmc_card_removed() which upper layers can use
to determine immediately if a card has been removed.  This
function should be called after an I/O request fails so that
all queued I/O requests can be errored out immediately
instead of waiting for the card device to be removed.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/core/core.c  |   32 ++++++++++++++++++++++++++++++++
 drivers/mmc/core/core.h  |    3 +++
 drivers/mmc/core/mmc.c   |   12 +++++++++++-
 drivers/mmc/core/sd.c    |   12 +++++++++++-
 drivers/mmc/core/sdio.c  |   11 ++++++++++-
 include/linux/mmc/card.h |    1 +
 include/linux/mmc/core.h |    2 ++
 7 files changed, 70 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 271efea..c317564 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2049,6 +2049,38 @@ static int mmc_rescan_try_freq(struct mmc_host *host, unsigned freq)
 	return -EIO;
 }

+int _mmc_card_removed(struct mmc_host *host, int detect_change)
+{
+	int ret;
+
+	if (!(host->caps & MMC_CAP_NONREMOVABLE) || !host->bus_ops->alive)
+		return 0;
+
+	if (!host->card || (host->card->state & MMC_CARD_REMOVED))
+		return 1;
+
+	/*
+	 * The card will be considered alive unless we have been asked to detect
+	 * a change or host requires polling to provide card detection.
+	 */
+	if (!detect_change && !(host->caps & MMC_CAP_NEEDS_POLL))
+		return 0;
+
+	ret = host->bus_ops->alive(host);
+	if (ret)
+		host->card->state |= MMC_CARD_REMOVED;
+
+	return ret;
+}
+
+int mmc_card_removed(struct mmc_host *host)
+{
+	WARN_ON(!host->claimed);
+
+	return _mmc_card_removed(host, work_pending(&host->detect.work));
+}
+EXPORT_SYMBOL(mmc_card_removed);
+
 void mmc_rescan(struct work_struct *work)
 {
 	static const unsigned freqs[] = { 400000, 300000, 200000, 100000 };
diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
index 14664f1..4b6b10e 100644
--- a/drivers/mmc/core/core.h
+++ b/drivers/mmc/core/core.h
@@ -24,6 +24,7 @@ struct mmc_bus_ops {
 	int (*resume)(struct mmc_host *);
 	int (*power_save)(struct mmc_host *);
 	int (*power_restore)(struct mmc_host *);
+	int (*alive)(struct mmc_host *);
 };

 void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops);
@@ -59,6 +60,8 @@ void mmc_rescan(struct work_struct *work);
 void mmc_start_host(struct mmc_host *host);
 void mmc_stop_host(struct mmc_host *host);

+int _mmc_card_removed(struct mmc_host *host, int detect_change);
+
 int mmc_attach_mmc(struct mmc_host *host);
 int mmc_attach_sd(struct mmc_host *host);
 int mmc_attach_sdio(struct mmc_host *host);
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index a1223bd..5841d08 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1104,6 +1104,14 @@ static void mmc_remove(struct mmc_host *host)
 }

 /*
+ * Card detection - card is alive.
+ */
+static int mmc_alive(struct mmc_host *host)
+{
+	return mmc_send_status(host->card, NULL);
+}
+
+/*
  * Card detection callback from host.
  */
 static void mmc_detect(struct mmc_host *host)
@@ -1118,7 +1126,7 @@ static void mmc_detect(struct mmc_host *host)
 	/*
 	 * Just check if our card has been removed.
 	 */
-	err = mmc_send_status(host->card, NULL);
+	err = _mmc_card_removed(host, 1);

 	mmc_release_host(host);

@@ -1223,6 +1231,7 @@ static const struct mmc_bus_ops mmc_ops = {
 	.suspend = NULL,
 	.resume = NULL,
 	.power_restore = mmc_power_restore,
+	.alive = mmc_alive,
 };

 static const struct mmc_bus_ops mmc_ops_unsafe = {
@@ -1233,6 +1242,7 @@ static const struct mmc_bus_ops mmc_ops_unsafe = {
 	.suspend = mmc_suspend,
 	.resume = mmc_resume,
 	.power_restore = mmc_power_restore,
+	.alive = mmc_alive,
 };

 static void mmc_attach_bus_ops(struct mmc_host *host)
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 1d5a3bd..82855ed 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -1018,6 +1018,14 @@ static void mmc_sd_remove(struct mmc_host *host)
 }

 /*
+ * Card detection - card is alive.
+ */
+static int mmc_sd_alive(struct mmc_host *host)
+{
+	return mmc_send_status(host->card, NULL);
+}
+
+/*
  * Card detection callback from host.
  */
 static void mmc_sd_detect(struct mmc_host *host)
@@ -1032,7 +1040,7 @@ static void mmc_sd_detect(struct mmc_host *host)
 	/*
 	 * Just check if our card has been removed.
 	 */
-	err = mmc_send_status(host->card, NULL);
+	err = _mmc_card_removed(host, 1);

 	mmc_release_host(host);

@@ -1101,6 +1109,7 @@ static const struct mmc_bus_ops mmc_sd_ops = {
 	.suspend = NULL,
 	.resume = NULL,
 	.power_restore = mmc_sd_power_restore,
+	.alive = mmc_sd_alive,
 };

 static const struct mmc_bus_ops mmc_sd_ops_unsafe = {
@@ -1109,6 +1118,7 @@ static const struct mmc_bus_ops mmc_sd_ops_unsafe = {
 	.suspend = mmc_sd_suspend,
 	.resume = mmc_sd_resume,
 	.power_restore = mmc_sd_power_restore,
+	.alive = mmc_sd_alive,
 };

 static void mmc_sd_attach_bus_ops(struct mmc_host *host)
diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 8c04f7f..ca5c4f9 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -820,6 +820,14 @@ static void mmc_sdio_remove(struct mmc_host *host)
 }

 /*
+ * Card detection - card is alive.
+ */
+static int mmc_sdio_alive(struct mmc_host *host)
+{
+	return mmc_select_card(host->card);
+}
+
+/*
  * Card detection callback from host.
  */
 static void mmc_sdio_detect(struct mmc_host *host)
@@ -841,7 +849,7 @@ static void mmc_sdio_detect(struct mmc_host *host)
 	/*
 	 * Just check if our card has been removed.
 	 */
-	err = mmc_select_card(host->card);
+	err = _mmc_card_removed(host, 1);

 	mmc_release_host(host);

@@ -1019,6 +1027,7 @@ static const struct mmc_bus_ops mmc_sdio_ops = {
 	.suspend = mmc_sdio_suspend,
 	.resume = mmc_sdio_resume,
 	.power_restore = mmc_sdio_power_restore,
+	.alive = mmc_sdio_alive,
 };


diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 534974c..c81b09f 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -209,6 +209,7 @@ struct mmc_card {
 #define MMC_STATE_HIGHSPEED_DDR (1<<4)		/* card is in high speed mode */
 #define MMC_STATE_ULTRAHIGHSPEED (1<<5)		/* card is in ultra high speed mode */
 #define MMC_CARD_SDXC		(1<<6)		/* card is SDXC */
+#define MMC_CARD_REMOVED	(1<<7)		/* card has been removed */
 	unsigned int		quirks; 	/* card quirks */
 #define MMC_QUIRK_LENIENT_FN0	(1<<0)		/* allow SDIO FN0 writes outside of the VS CCCR range */
 #define MMC_QUIRK_BLKSZ_FOR_BYTE_MODE (1<<1)	/* use func->cur_blksize */
diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
index 174a844..8604472 100644
--- a/include/linux/mmc/core.h
+++ b/include/linux/mmc/core.h
@@ -180,6 +180,8 @@ extern int mmc_try_claim_host(struct mmc_host *host);

 extern int mmc_flush_cache(struct mmc_card *);

+extern int mmc_card_removed(struct mmc_host *host);
+
 /**
  *	mmc_claim_host - exclusively claim a host
  *	@host: mmc host to claim
-- 
1.7.6.4