Hi,
On 31/10/2016 11:14, Alex Lemberg wrote:
Hi,
By the eMMC5.0 spec, before sending Sleep command (CMD5), hosts may set the
POWER_OFF_NOTIFICATION byte to SLEEP_NOTIFICATION (0x04).
Isn’t this a case in this patch?
If yes, why not sending SLEEP_NOTIFICATION instead of POWER_OFF_SHORT?
I cannot tell if this was really what the Hynix engineers meant here.
In the past we had a discussion on this topic, but the solution became more complicated because
of possibly long timeout (max 83 seconds) on SLEEP_NOTIFICATION.
https://marc.info/?t=143374696600002&r=1&w=1
But still, in case we want to support POWER_OFF_NOTIFICATION before Sleep command,
and in case we want to be eMMC spec aligned, I believe the right thing to do
is to support SLEEP_NOTIFICATION…
I can give a try to this patchset to see if it solves the issue and get
back to you afterward.
Regards,
Thierry
Thanks,
Alex
On 10/27/16, 10:49 PM, "linux-mmc-owner@xxxxxxxxxxxxxxx on behalf of Ulf Hansson" <linux-mmc-owner@xxxxxxxxxxxxxxx on behalf of ulf.hansson@xxxxxxxxxx> wrote:
On 27 October 2016 at 17:06, Thierry Escande
<thierry.escande@xxxxxxxxxxxxx> wrote:
Hi Ulf,
On 25/10/2016 12:03, Ulf Hansson wrote:
On 3 October 2016 at 16:19, Thierry Escande
<thierry.escande@xxxxxxxxxxxxx> wrote:
From: zhaojohn <john.zhao@xxxxxxxxx>
Hynix eMMC devices sometimes take 50% longer to resume from sleep.
Based on a recommendation from Hynix, send a Power-Off Notification
before going to S3 to restore a resume time consistently within spec.
Could you also share what mmc controller and SoC you get this results
from?
More precisely, are you using MMC_CAP_WAIT_WHILE_BUSY?
This occurs on a braswell based chromebook, using the acpi sdhci controller.
So yes, using MMC_CAP_WAIT_WHILE_BUSY.
[...]
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index f2d185c..46a4562 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1925,8 +1925,14 @@ static int _mmc_suspend(struct mmc_host *host,
bool is_suspend)
if (mmc_can_poweroff_notify(host->card) &&
((host->caps2 & MMC_CAP2_FULL_PWR_CYCLE) || !is_suspend))
err = mmc_poweroff_notify(host->card, notify_type);
- else if (mmc_can_sleep(host->card))
+ else if (mmc_can_sleep(host->card)) {
+ if (host->card->quirks &
MMC_QUIRK_NOTIFY_POWEROFF_ON_SLEEP) {
+ err = mmc_poweroff_notify(host->card,
notify_type);
+ if (err)
+ goto out;
+ }
So, I am curious to know from a power management point of view; how
does the card behave comparing the sleep and power off notification
command?
Is the card in a low power state after the power off notification has
been received? If so, did you manage to do some measurement for that
or perhaps the data-sheet tells about this? It would be interesting to
know if there were any differences between sleep and power off
notification in this regards.
I do not have any clue about that. It appears only with Hynix emmc and the
fix has been approved by Hynix engineers... It seems that if not powered
off, the firmware does some garbage collection when resuming and it takes
more time...
Okay, I see. So before I continue reviewing, can you please also tell
what regulators to the card that is being cut while powering off in
this path.
VMMC, VQMMC?
Kind regards
Uffe
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