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authorAdrian Hunter <adrian.hunter@nokia.com>2009-09-23 01:45:01 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2009-09-23 16:39:36 +0200
commitb62f622812c5aaacad217fd8f4445562b917df6d (patch)
tree51ab6f42fa7be7460fb3d6f922f0ad9bacbd54f3 /drivers
parentomap_hsmmc: code refactoring (diff)
downloadlinux-b62f622812c5aaacad217fd8f4445562b917df6d.tar.xz
linux-b62f622812c5aaacad217fd8f4445562b917df6d.zip
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> Acked-by: Matt Fleming <matt@console-pimps.org> Cc: Ian Molton <ian@mnementh.co.uk> Cc: "Roberto A. Foglietta" <roberto.foglietta@gmail.com> Cc: Jarkko Lavinen <jarkko.lavinen@nokia.com> Cc: Denis Karpov <ext-denis.2.karpov@nokia.com> Cc: Pierre Ossman <pierre@ossman.eu> Cc: Philip Langdale <philipl@overt.org> Cc: "Madhusudhan" <madhu.cr@ti.com> Cc: <linux-mmc@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/mmc/host/omap_hsmmc.c63
1 files changed, 61 insertions, 2 deletions
diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 20746e4f00b3..a20fafecfc60 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -167,6 +167,8 @@ struct omap_hsmmc_host {
int context_loss;
int dpm_state;
int vdd;
+ int protect_card;
+ int reqs_blocked;
struct omap_mmc_platform_data *pdata;
};
@@ -351,6 +353,9 @@ 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);
@@ -786,6 +791,30 @@ 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
*/
@@ -803,8 +832,10 @@ 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);
@@ -1040,8 +1071,32 @@ 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()) {
spin_lock_irqsave(&host->irq_lock, host->flags);
+ /*
+ * 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;
+ spin_unlock_irqrestore(&host->irq_lock, host->flags);
+ 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);
@@ -1732,6 +1787,8 @@ 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) {
@@ -1897,6 +1954,8 @@ 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)