While trying to suspend the mmc host there could still be ongoing requests that we need to wait for. At the same time a device driver must respond to a suspend request rather quickly.
Instead of potentially wait "forever" by claiming the host we now "try" to claim the host instead. If it fails, -EBUSY is returned. Signed-off-by: Ulf Hansson <[email protected]> --- drivers/mmc/core/core.c | 42 +++++++++++++++++++++++++++--------------- 1 files changed, 27 insertions(+), 15 deletions(-) diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 61d7730..b900932 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -2121,21 +2121,33 @@ int mmc_suspend_host(struct mmc_host *host) mmc_bus_get(host); if (host->bus_ops && !host->bus_dead) { - if (host->bus_ops->suspend) - err = host->bus_ops->suspend(host); - if (err == -ENOSYS || !host->bus_ops->resume) { - /* - * We simply "remove" the card in this case. - * It will be redetected on resume. - */ - if (host->bus_ops->remove) - host->bus_ops->remove(host); - mmc_claim_host(host); - mmc_detach_bus(host); - mmc_power_off(host); - mmc_release_host(host); - host->pm_flags = 0; - err = 0; + + /* + * A long response time is not acceptable for device drivers + * when doing suspend. Prevent mmc_claim_host in the suspend + * sequence, to potentially wait "forever" by trying to + * pre-claim the host. + */ + if (mmc_try_claim_host(host)) { + if (host->bus_ops->suspend) + err = host->bus_ops->suspend(host); + if (err == -ENOSYS || !host->bus_ops->resume) { + /* + * We simply "remove" the card in this case. + * It will be redetected on resume. + */ + if (host->bus_ops->remove) + host->bus_ops->remove(host); + mmc_claim_host(host); + mmc_detach_bus(host); + mmc_power_off(host); + mmc_release_host(host); + host->pm_flags = 0; + err = 0; + } + mmc_do_release_host(host); + } else { + err = -EBUSY; } } mmc_bus_put(host); -- 1.7.5.4 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
