diff mbox series

[PATCH/RFC,v4,3/4] mmc: core: Call mmc_poweroff_nofity() if regulators are disabled

Message ID 1593163942-5087-4-git-send-email-yoshihiro.shimoda.uh@renesas.com (mailing list archive)
State New, archived
Headers show
Series treewide: add regulator condition on _mmc_suspend() | expand

Commit Message

Yoshihiro Shimoda June 26, 2020, 9:32 a.m. UTC
If regulator_is_enabled() of both vmmc and vqmmc returns false,
_mmc_suspend() should call mmc_poweroff_nofity() instead of
mmc_sleep().

Note that this is possible to happen when the regulator-fixed driver
turns the vmmc and vqmmc off by firmware like PSCI while the system
is suspended.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
---
 drivers/mmc/core/mmc.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

Comments

Mark Brown June 26, 2020, 3:13 p.m. UTC | #1
On Fri, Jun 26, 2020 at 06:32:21PM +0900, Yoshihiro Shimoda wrote:

> If regulator_is_enabled() of both vmmc and vqmmc returns false,
> _mmc_suspend() should call mmc_poweroff_nofity() instead of
> mmc_sleep().

This is possibly something it makes sense to do, if the power did
suddenly vanish on the device then using a separate cleanup path for
that seems sensible (it's probably something worth complaining loudly
about).  Registering for notification on power loss might also be
sensible.

> Note that this is possible to happen when the regulator-fixed driver
> turns the vmmc and vqmmc off by firmware like PSCI while the system
> is suspended.

This is not a good interface, if there's a need to query the state over
suspend then we should query the state over suspend rather than trying
to somehow shoehorn it via the runtime enable state which is going to
break any other users and relies on the regulator driver doing dodgy
stuff representing the enable state.
Sergei Shtylyov June 26, 2020, 3:53 p.m. UTC | #2
Hello!

On 06/26/2020 12:32 PM, Yoshihiro Shimoda wrote:

> If regulator_is_enabled() of both vmmc and vqmmc returns false,
> _mmc_suspend() should call mmc_poweroff_nofity() instead of
                                          ^^^^^^
  That hard word again. :-)        

> mmc_sleep().
> 
> Note that this is possible to happen when the regulator-fixed driver
> turns the vmmc and vqmmc off by firmware like PSCI while the system
> is suspended.
> 
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
[...]

MBR, Sergei
Yoshihiro Shimoda June 29, 2020, 2:49 a.m. UTC | #3
Hi Mark,

> From: Mark Brown, Sent: Saturday, June 27, 2020 12:14 AM
> 
> On Fri, Jun 26, 2020 at 06:32:21PM +0900, Yoshihiro Shimoda wrote:
> > Note that this is possible to happen when the regulator-fixed driver
> > turns the vmmc and vqmmc off by firmware like PSCI while the system
> > is suspended.
> 
> This is not a good interface, if there's a need to query the state over
> suspend then we should query the state over suspend rather than trying
> to somehow shoehorn it via the runtime enable state which is going to
> break any other users and relies on the regulator driver doing dodgy
> stuff representing the enable state.

I understood it.
So, as I mentioned other email thread, I'm thinking adding a new property
into MMC is better.

Best regards,
Yoshihiro Shimoda
Yoshihiro Shimoda June 29, 2020, 5:16 a.m. UTC | #4
Hello!

> From: Sergei Shtylyov, Sent: Saturday, June 27, 2020 12:54 AM
> 
> Hello!
> 
> On 06/26/2020 12:32 PM, Yoshihiro Shimoda wrote:
> 
> > If regulator_is_enabled() of both vmmc and vqmmc returns false,
> > _mmc_suspend() should call mmc_poweroff_nofity() instead of
>                                           ^^^^^^
>   That hard word again. :-)

Oops! Thank you for pointed it out!
# Also, the subject was incorrect...

Best regards,
Yoshihiro Shimoda
diff mbox series

Patch

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 4203303..75df5f8 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -12,6 +12,7 @@ 
 #include <linux/slab.h>
 #include <linux/stat.h>
 #include <linux/pm_runtime.h>
+#include <linux/regulator/consumer.h>
 
 #include <linux/mmc/host.h>
 #include <linux/mmc/card.h>
@@ -2022,6 +2023,18 @@  static void mmc_detect(struct mmc_host *host)
 	}
 }
 
+static bool mmc_regulators_are_disabled(struct mmc_host *host)
+{
+	if (IS_ERR(host->supply.vmmc) ||
+	    regulator_is_enabled(host->supply.vmmc))
+		return false;
+	if (IS_ERR(host->supply.vqmmc) ||
+	    regulator_is_enabled(host->supply.vqmmc))
+		return false;
+
+	return true;
+}
+
 static int _mmc_suspend(struct mmc_host *host, bool is_suspend)
 {
 	int err = 0;
@@ -2038,7 +2051,8 @@  static int _mmc_suspend(struct mmc_host *host, bool is_suspend)
 		goto out;
 
 	if (mmc_can_poweroff_notify(host->card) &&
-		((host->caps2 & MMC_CAP2_FULL_PWR_CYCLE) || !is_suspend))
+	    ((host->caps2 & MMC_CAP2_FULL_PWR_CYCLE) || !is_suspend ||
+	     mmc_regulators_are_disabled(host)))
 		err = mmc_poweroff_notify(host->card, notify_type);
 	else if (mmc_can_sleep(host->card))
 		err = mmc_sleep(host);