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Subject[PATCH 29/32] omap_hsmmc: protect the card when the cover is open
From 9b524a70c3d8f3d138646630bb2144c9895af47a Mon Sep 17 00:00:00 2001
From: Adrian Hunter <adrian.hunter@nokia.com>
Date: Fri, 22 May 2009 16:53:49 +0300
Subject: [PATCH] omap_hsmmc: protect the card when the cover is open

Depending on the manufacturer, there is a small possibility that
removing a card while it is being written to, can render the
card permanently unusable. To prevent that, the card is made
inaccessible when the cover is open.

Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
---
drivers/mmc/host/omap_hsmmc.c | 63 +++++++++++++++++++++++++++++++++++++++-
1 files changed, 61 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 5055d52..2570bfe 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -163,6 +163,8 @@ struct omap_hsmmc_host {
int context_loss;
int dpm_state;
int vdd;
+ int protect_card;
+ int reqs_blocked;

struct omap_mmc_platform_data *pdata;
};
@@ -347,6 +349,9 @@ static void send_init_stream(struct omap_hsmmc_host *host)
int reg = 0;
unsigned long timeout;

+ if (host->protect_card)
+ return;
+
disable_irq(host->irq);
OMAP_HSMMC_WRITE(host->base, CON,
OMAP_HSMMC_READ(host->base, CON) | INIT_STREAM);
@@ -771,6 +776,30 @@ err:
return ret;
}

+/* Protect the card while the cover is open */
+static void omap_hsmmc_protect_card(struct omap_hsmmc_host *host)
+{
+ if (!mmc_slot(host).get_cover_state)
+ return;
+
+ host->reqs_blocked = 0;
+ if (mmc_slot(host).get_cover_state(host->dev, host->slot_id)) {
+ if (host->protect_card) {
+ printk(KERN_INFO "%s: cover is closed, "
+ "card is now accessible\n",
+ mmc_hostname(host->mmc));
+ host->protect_card = 0;
+ }
+ } else {
+ if (!host->protect_card) {
+ printk(KERN_INFO "%s: cover is open, "
+ "card is now inaccessible\n",
+ mmc_hostname(host->mmc));
+ host->protect_card = 1;
+ }
+ }
+}
+
/*
* Work Item to notify the core about card insertion/removal
*/
@@ -788,8 +817,10 @@ static void omap_hsmmc_detect(struct work_struct *work)

if (slot->card_detect)
carddetect = slot->card_detect(slot->card_detect_irq);
- else
+ else {
+ omap_hsmmc_protect_card(host);
carddetect = -ENOSYS;
+ }

if (carddetect) {
mmc_detect_change(host->mmc, (HZ * 200) / 1000);
@@ -1025,8 +1056,32 @@ static void omap_hsmmc_request(struct mmc_host *mmc, struct mmc_request *req)
* interrupts, but not if we are already in interrupt context i.e.
* retries.
*/
- if (!in_interrupt())
+ if (!in_interrupt()) {
disable_irq(host->irq);
+ /*
+ * Protect the card from I/O if there is a possibility
+ * it can be removed.
+ */
+ if (host->protect_card) {
+ if (host->reqs_blocked < 3) {
+ /*
+ * Ensure the controller is left in a consistent
+ * state by resetting the command and data state
+ * machines.
+ */
+ omap_hsmmc_reset_controller_fsm(host, SRD);
+ omap_hsmmc_reset_controller_fsm(host, SRC);
+ host->reqs_blocked += 1;
+ }
+ req->cmd->error = -EBADF;
+ if (req->data)
+ req->data->error = -EBADF;
+ enable_irq(host->irq);
+ mmc_request_done(mmc, req);
+ return;
+ } else if (host->reqs_blocked)
+ host->reqs_blocked = 0;
+ }
WARN_ON(host->mrq != NULL);
host->mrq = req;
err = omap_hsmmc_prepare_data(host, req);
@@ -1715,6 +1770,8 @@ static int __init omap_hsmmc_probe(struct platform_device *pdev)

mmc_host_lazy_disable(host->mmc);

+ omap_hsmmc_protect_card(host);
+
mmc_add_host(mmc);

if (mmc_slot(host).name != NULL) {
@@ -1880,6 +1937,8 @@ static int omap_hsmmc_resume(struct platform_device *pdev)
"Unmask interrupt failed\n");
}

+ omap_hsmmc_protect_card(host);
+
/* Notify the core to resume the host */
ret = mmc_resume_host(host->mmc);
if (ret == 0)
--
1.5.6.3


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