mmc: core: Prevent too long response times for suspend (b6ad726e) · Commits · 戴 / test

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@stericsson.com> Reviewed-by:

Sujit Reddy Thumma <sthumma@codeaurora.org> Acked-by:

Linus Walleij <linus.walleij@linaro.org> Signed-off-by:

Chris Ball <cjb@laptop.org>

drivers/mmc/core/core.c

+27 −15

Original line number	Diff line number	Diff line
		@@ -2294,6 +2294,14 @@ int mmc_suspend_host(struct mmc_host *host)

		mmc_bus_get(host);
		if (host->bus_ops && !host->bus_dead) {

		/*
		* 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) {
		@@ -2310,6 +2318,10 @@ int mmc_suspend_host(struct mmc_host *host)
		host->pm_flags = 0;
		err = 0;
		}
		mmc_do_release_host(host);
		} else {
		err = -EBUSY;
		}
		}
		mmc_bus_put(host);

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