Re: [PATCH V1] mmc: sdhci-msm: Set IO pins in low power state during suspend

From: Veerabhadrarao Badiganti
Date: Mon Jul 27 2020 - 06:21:53 EST

On 7/24/2020 3:06 PM, Ulf Hansson wrote:
On Tue, 14 Jul 2020 at 16:12, Veerabhadrarao Badiganti
<vbadigan@xxxxxxxxxxxxxx> wrote:

On 7/13/2020 9:26 PM, Veerabhadrarao Badiganti wrote:
On 7/11/2020 5:49 AM, Matthias Kaehlcke wrote:

On Fri, Jul 10, 2020 at 04:28:36PM +0530, Veerabhadrarao Badiganti
Hi Mathias,

On 7/10/2020 6:22 AM, Matthias Kaehlcke wrote:

On Wed, Jul 08, 2020 at 06:41:20PM +0530, Veerabhadrarao Badiganti
Configure SDHC IO pins with low power configuration when the driver
is in suspend state.

Signed-off-by: Veerabhadrarao Badiganti <vbadigan@xxxxxxxxxxxxxx>
drivers/mmc/host/sdhci-msm.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)

diff --git a/drivers/mmc/host/sdhci-msm.c
index 392d41d57a6e..efd2bae1430c 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -15,6 +15,7 @@
#include <linux/iopoll.h>
#include <linux/regulator/consumer.h>
#include <linux/interconnect.h>
+#include <linux/pinctrl/consumer.h>
#include "sdhci-pltfm.h"
#include "cqhci.h"
@@ -1352,6 +1353,19 @@ static void
sdhci_msm_set_uhs_signaling(struct sdhci_host *host,
sdhci_msm_hs400(host, &mmc->ios);
+static int sdhci_msm_set_pincfg(struct sdhci_msm_host *msm_host,
bool level)
+ struct platform_device *pdev = msm_host->pdev;
+ int ret;
+ if (level)
+ ret = pinctrl_pm_select_default_state(&pdev->dev);
+ else
+ ret = pinctrl_pm_select_sleep_state(&pdev->dev);
+ return ret;
static int sdhci_msm_set_vmmc(struct mmc_host *mmc)
if (IS_ERR(mmc->supply.vmmc))
@@ -1596,6 +1610,9 @@ static void sdhci_msm_handle_pwr_irq(struct
sdhci_host *host, int irq)
ret = sdhci_msm_set_vqmmc(msm_host, mmc,
pwr_state & REQ_BUS_ON);
if (!ret)
+ ret = sdhci_msm_set_pincfg(msm_host,
+ pwr_state & REQ_BUS_ON);
+ if (!ret)
I happened to have a debug patch in my tree which logs when regulators
are enabled/disabled, with this patch I see the SD card regulator
toggling constantly after returning from the first system suspend.

I added more logs:

[ 1156.085819] DBG: sdhci_msm_set_pincfg: level = 0 (ret: 0)
[ 1156.248936] DBG: sdhci_msm_set_pincfg: level = 1 (ret: 0)
[ 1156.301989] DBG: sdhci_msm_set_pincfg: level = 0 (ret: 0)
[ 1156.462383] DBG: sdhci_msm_set_pincfg: level = 1 (ret: 0)
[ 1156.525988] DBG: sdhci_msm_set_pincfg: level = 0 (ret: 0)
[ 1156.670372] DBG: sdhci_msm_set_pincfg: level = 1 (ret: 0)
[ 1156.717935] DBG: sdhci_msm_set_pincfg: level = 0 (ret: 0)
[ 1156.878122] DBG: sdhci_msm_set_pincfg: level = 1 (ret: 0)
[ 1156.928134] DBG: sdhci_msm_set_pincfg: level = 0 (ret: 0)

This is on an SC7180 platform. It doesn't run an upstream kernel
but v5.4 with plenty of upstream patches.
I have verified this on couple of sc7180 targets (on Chrome platform
Chrome kernel).
But didn't see any issue. Its working as expected.
Did you test system suspend too? At least in the Chrome OS kernel
tree system
suspend is not supported yet in the main branch, you'd need a pile of
extra patches to get it to work. This is expected to change soon
though :)
Yes. I have verified with system suspend-resume scenario.
Sorry forgot to mention this point explicitly in last response.

I believe all the needed patches were present on qcom internal tree.
Suspend-resume is working fine on sc7180 qcom chrome tree.

Thanks Matthias. I cloud reproduce the issue on device without SDcard.

Without SDcard inserted, cd-gpio (SD card detect GPIO) is getting read
as active HIGH
(as if card is inserted) during system-resume, resulting SDcard probe/scan.

After that its triggering interrupt again when pinctrl config is applied
during SDcard
power-up sequence (as part of probe/scan) which is again triggering
sdcard scan.

I will have to change SDcard cd-gpio sleep config to fix this issue like

diff --git a/arch/arm64/boot/dts/qcom/sc7180.dtsi
index e2230f47a17d..9266d514e163 100644
--- a/arch/arm64/boot/dts/qcom/sc7180.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7180.dtsi
@@ -2447,7 +2447,7 @@

pinconf-sd-cd {
pins = "gpio69";
- bias-disable;
+ bias-pull-up;
drive-strength = <2>;

I will check more on why its getting read as active HIGH during resume.

Let me know if you are observing this issue constantly on multiple
boards, I
will share you
a debug patch to check it further.
I currently have only one board with the SD card slot populated, I might
get another one next week.

The toggling occurs only when no SD card is inserted.


Thanks for testing and for looking into this. Perhaps I should drop
the $subject patch then?
Hi Uffe,

No need to drop this. We could root-casue the issue. Its a board specific issue.
This particular platform/board doesn't have external pull-up on the cd-gpio pin.

So internal pull-up config has to be applied on cd-gpio all the time.
We posted this dt change to enable internal pull