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authorUlf Hansson <ulf.hansson@linaro.org>2013-06-10 19:03:45 +0400
committerChris Ball <cjb@laptop.org>2013-06-27 20:39:21 +0400
commit43235679341510f58a86eb75ab23cbae4bdc59b8 (patch)
tree769bffa7f730d317dc4690c0ba15c244e3de3cbd /drivers/mmc
parent486fdbbc1483504cde0314e33e47bc32e9d38186 (diff)
downloadlinux-43235679341510f58a86eb75ab23cbae4bdc59b8.tar.xz
mmc: core: Enable power_off_notify for eMMC shutdown sequence
In suspend mode it is important to save power. If the host is able to cut buth vcc and vccq, the MMC_CAP2_POWEROFF_NOTIFY shall be set. It will mean the card will be completely powered down at suspend and the power off notification cmd will be sent prior power down. It seems common not being able to cut both vcc and vccq for a host. In this situation we issue the sleep cmd in favor of the power off notification cmd, to save more power. While maintainng the above policy, we also want to make use of the power off notification in the shutdown sequence, even in the case were the host has not set MMC_CAP2_POWEROFF_NOTIFY, since we know vcc and vccq will regardless be cut. We accomplish this by always enabling the power off notification byte in the EXT_CSD and issue the power off notification when either MMC_CAP2_POWEROFF_NOTIFY is set or we are executing a shutdown. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/core/mmc.c9
1 files changed, 4 insertions, 5 deletions
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index f670c285613d..e2946a98a1fa 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1041,11 +1041,9 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
}
/*
- * If the host supports the power_off_notify capability then
- * set the notification byte in the ext_csd register of device
+ * Enable power_off_notification byte in the ext_csd register
*/
- if ((host->caps2 & MMC_CAP2_POWEROFF_NOTIFY) &&
- (card->ext_csd.rev >= 6)) {
+ if (card->ext_csd.rev >= 6) {
err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
EXT_CSD_POWER_OFF_NOTIFICATION,
EXT_CSD_POWER_ON,
@@ -1485,7 +1483,8 @@ static int _mmc_suspend(struct mmc_host *host, bool is_suspend)
if (err)
goto out;
- if (mmc_can_poweroff_notify(host->card))
+ if (mmc_can_poweroff_notify(host->card) &&
+ ((host->caps2 & MMC_CAP2_POWEROFF_NOTIFY) || !is_suspend))
err = mmc_poweroff_notify(host->card, notify_type);
else if (mmc_can_sleep(host->card))
err = mmc_sleep(host);