diff options
| author | Adrian Hunter <adrian.hunter@nokia.com> | 2009-09-22 16:44:30 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-09-23 07:39:33 -0700 |
| commit | 319a3f1429c91147058ac26c5f5bac8ec1730bc6 (patch) | |
| tree | 4a39ff034f7e9b57b903997f818eee5304657991 /drivers/mmc/core | |
| parent | 8ea926b22e2d13238e4d65d8f61c48fe424e6f4f (diff) | |
mmc: allow host claim / release nesting
This change allows the MMC host to be claimed in situations where the host
may or may not have already been claimed. Also 'mmc_try_claim_host()' is
now exported.
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/mmc/core')
| -rw-r--r-- | drivers/mmc/core/core.c | 34 |
1 files changed, 25 insertions, 9 deletions
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index fb24a096dba..02f2b1871a3 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -461,16 +461,18 @@ int __mmc_claim_host(struct mmc_host *host, atomic_t *abort) while (1) { set_current_state(TASK_UNINTERRUPTIBLE); stop = abort ? atomic_read(abort) : 0; - if (stop || !host->claimed) + if (stop || !host->claimed || host->claimer == current) break; spin_unlock_irqrestore(&host->lock, flags); schedule(); spin_lock_irqsave(&host->lock, flags); } set_current_state(TASK_RUNNING); - if (!stop) + if (!stop) { host->claimed = 1; - else + host->claimer = current; + host->claim_cnt += 1; + } else wake_up(&host->wq); spin_unlock_irqrestore(&host->lock, flags); remove_wait_queue(&host->wq, &wait); @@ -481,29 +483,43 @@ int __mmc_claim_host(struct mmc_host *host, atomic_t *abort) EXPORT_SYMBOL(__mmc_claim_host); -static int mmc_try_claim_host(struct mmc_host *host) +/** + * mmc_try_claim_host - try exclusively to claim a host + * @host: mmc host to claim + * + * Returns %1 if the host is claimed, %0 otherwise. + */ +int mmc_try_claim_host(struct mmc_host *host) { int claimed_host = 0; unsigned long flags; spin_lock_irqsave(&host->lock, flags); - if (!host->claimed) { + if (!host->claimed || host->claimer == current) { host->claimed = 1; + host->claimer = current; + host->claim_cnt += 1; claimed_host = 1; } spin_unlock_irqrestore(&host->lock, flags); return claimed_host; } +EXPORT_SYMBOL(mmc_try_claim_host); static void mmc_do_release_host(struct mmc_host *host) { unsigned long flags; spin_lock_irqsave(&host->lock, flags); - host->claimed = 0; - spin_unlock_irqrestore(&host->lock, flags); - - wake_up(&host->wq); + if (--host->claim_cnt) { + /* Release for nested claim */ + spin_unlock_irqrestore(&host->lock, flags); + } else { + host->claimed = 0; + host->claimer = NULL; + spin_unlock_irqrestore(&host->lock, flags); + wake_up(&host->wq); + } } void mmc_host_deeper_disable(struct work_struct *work) |