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 <ulf.hansson@xxxxxxxxxxxxxx>
---
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
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