>From 9b524a70c3d8f3d138646630bb2144c9895af47a Mon Sep 17 00:00:00 2001 From: Adrian Hunter <[email protected]> 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 <[email protected]> --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
