From 6f8d7022a842809aeb24db1d15669198ef02c131 Mon Sep 17 00:00:00 2001 From: Barry Song Date: Thu, 6 Oct 2011 20:34:46 +0200 Subject: [PATCH] PM / Hibernate: Add resumewait param to support MMC-like devices as resume file Some devices like MMC are async detected very slow. For example, drivers/mmc/host/sdhci.c launches a 200ms delayed work to detect MMC partitions then add disk. We have wait_for_device_probe() and scsi_complete_async_scans() before calling swsusp_check(), but it is not enough to wait for MMC. This patch adds resumewait kernel param just like rootwait so that we have enough time to wait until MMC is ready. The difference is that we wait for resume partition whereas rootwait waits for rootfs partition (which may be on a different device). This patch will make hibernation support many embedded products without SCSI devices, but with devices like MMC. [rjw: Modified the changelog slightly.] Signed-off-by: Barry Song Reviewed-by: Valdis Kletnieks Signed-off-by: Rafael J. Wysocki --- Documentation/kernel-parameters.txt | 4 ++++ kernel/power/hibernate.c | 16 ++++++++++++++++ 2 files changed, 20 insertions(+) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 854ed5ca7e3f..88a7b197a4eb 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2240,6 +2240,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. in units (needed only for swap files). See Documentation/power/swsusp-and-swap-files.txt + resumewait [HIBERNATION] Wait (indefinitely) for resume device to show up. + Useful for devices that are detected asynchronously + (e.g. USB and MMC devices). + hibernate= [HIBERNATION] noresume Don't check if there's a hibernation image present during boot. diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 7f44e5c26971..0f8785080cde 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -31,6 +32,7 @@ static int nocompress = 0; static int noresume = 0; +static int resume_wait = 0; static char resume_file[256] = CONFIG_PM_STD_PARTITION; dev_t swsusp_resume_device; sector_t swsusp_resume_block; @@ -736,6 +738,13 @@ static int software_resume(void) * to wait for this to finish. */ wait_for_device_probe(); + + if (resume_wait) { + while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0) + msleep(10); + async_synchronize_full(); + } + /* * We can't depend on SCSI devices being available after loading * one of their modules until scsi_complete_async_scans() is @@ -1064,7 +1073,14 @@ static int __init noresume_setup(char *str) return 1; } +static int __init resumewait_setup(char *str) +{ + resume_wait = 1; + return 1; +} + __setup("noresume", noresume_setup); __setup("resume_offset=", resume_offset_setup); __setup("resume=", resume_setup); __setup("hibernate=", hibernate_setup); +__setup("resumewait", resumewait_setup);