From d9adcc12860d76cf3401c6ab7c0406b15b356b7a Mon Sep 17 00:00:00 2001 From: Guennadi Liakhovetski Date: Thu, 14 Jun 2012 10:17:39 +0200 Subject: [PATCH] mmc: prohibit card detection when host is not ready Currently mmc host drivers have to decide whether to enable card detection before calling mmc_add_host() -- in which case a card insertion event can arrive before the host has been completely initialised -- or after mmc_add_host(), in which case the initial card detection can be problematic. This patch adds an explicit indication of when card detection should not be carried out. With it in place enabling card detection before calling mmc_add_host() should be safe. Similarly, disabling it again after calling mmc_remove_host() will avoid any races. Signed-off-by: Guennadi Liakhovetski Signed-off-by: Chris Ball --- drivers/mmc/core/core.c | 2 ++ drivers/mmc/core/host.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 8d00aef9523e..9503cabc96f1 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -2107,6 +2107,7 @@ void mmc_rescan(struct work_struct *work) void mmc_start_host(struct mmc_host *host) { host->f_init = max(freqs[0], host->f_min); + host->rescan_disable = 0; mmc_power_up(host); mmc_detect_change(host, 0); } @@ -2120,6 +2121,7 @@ void mmc_stop_host(struct mmc_host *host) spin_unlock_irqrestore(&host->lock, flags); #endif + host->rescan_disable = 1; cancel_delayed_work_sync(&host->detect); mmc_flush_scheduled_work(); diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c index 74cf29a504f4..597f189b4427 100644 --- a/drivers/mmc/core/host.c +++ b/drivers/mmc/core/host.c @@ -313,6 +313,8 @@ struct mmc_host *mmc_alloc_host(int extra, struct device *dev) if (!host) return NULL; + /* scanning will be enabled when we're ready */ + host->rescan_disable = 1; spin_lock(&mmc_host_lock); err = idr_get_new(&mmc_host_idr, host, &host->index); spin_unlock(&mmc_host_lock); -- 2.39.5