mmc: core: Prevent too long response times for suspend
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>
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@ -2294,21 +2294,33 @@ int mmc_suspend_host(struct mmc_host *host)
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mmc_bus_get(host);
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if (host->bus_ops && !host->bus_dead) {
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if (host->bus_ops->suspend)
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err = host->bus_ops->suspend(host);
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if (err == -ENOSYS || !host->bus_ops->resume) {
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/*
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* We simply "remove" the card in this case.
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* It will be redetected on resume.
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*/
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if (host->bus_ops->remove)
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host->bus_ops->remove(host);
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mmc_claim_host(host);
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mmc_detach_bus(host);
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mmc_power_off(host);
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mmc_release_host(host);
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host->pm_flags = 0;
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err = 0;
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/*
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* A long response time is not acceptable for device drivers
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* when doing suspend. Prevent mmc_claim_host in the suspend
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* sequence, to potentially wait "forever" by trying to
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* pre-claim the host.
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*/
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if (mmc_try_claim_host(host)) {
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if (host->bus_ops->suspend)
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err = host->bus_ops->suspend(host);
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if (err == -ENOSYS || !host->bus_ops->resume) {
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/*
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* We simply "remove" the card in this case.
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* It will be redetected on resume.
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*/
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if (host->bus_ops->remove)
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host->bus_ops->remove(host);
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mmc_claim_host(host);
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mmc_detach_bus(host);
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mmc_power_off(host);
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mmc_release_host(host);
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host->pm_flags = 0;
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err = 0;
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}
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mmc_do_release_host(host);
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} else {
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err = -EBUSY;
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}
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}
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mmc_bus_put(host);
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