Re: [PATCH v3 15/16] soc: mediatek: pm-domains: Add default power off flag

[Matthias Brugger]

On 27/10/2020 12:18, Weiyi Lu wrote:
On Tue, 2020-10-27 at 11:53 +0100, Matthias Brugger wrote:

On 26/10/2020 18:55, Enric Balletbo i Serra wrote:
From: Weiyi Lu <weiyi...@mediatek.com>

For some power domain, like conn on MT8192, it should be default OFF.
Because the power on/off control relies the function of connectivity chip
and its firmware. And if project choose other chip vendor solution,
those necessary connectivity functions will not provided.

Signed-off-by: Weiyi Lu <weiyi...@mediatek.com>
Signed-off-by: Enric Balletbo i Serra <enric.balle...@collabora.com>
---

Changes in v3: None
Changes in v2: None

   drivers/soc/mediatek/mtk-pm-domains.c | 23 +++++++++++++++++------
   drivers/soc/mediatek/mtk-pm-domains.h |  1 +
   2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/drivers/soc/mediatek/mtk-pm-domains.c 
b/drivers/soc/mediatek/mtk-pm-domains.c
index 63993076a544..fe0e955076a0 100644
--- a/drivers/soc/mediatek/mtk-pm-domains.c
+++ b/drivers/soc/mediatek/mtk-pm-domains.c
@@ -378,10 +378,16 @@ generic_pm_domain *scpsys_add_one_domain(struct scpsys 
*scpsys, struct device_no
         * software.  The unused domains will be switched off during
         * late_init time.
         */
-       ret = scpsys_power_on(&pd->genpd);
-       if (ret < 0) {
-               dev_err(scpsys->dev, "%pOF: failed to power on domain: %d\n", 
node, ret);
-               goto err_unprepare_clocks;
+       if (MTK_SCPD_CAPS(pd, MTK_SCPD_KEEP_DEFAULT_OFF)) {
+               if (scpsys_domain_is_on(pd))
+                       dev_warn(scpsys->dev,
+                                "%pOF: A default off power domain has been 
ON\n", node);
+       } else {
+               ret = scpsys_power_on(&pd->genpd);
+               if (ret < 0) {
+                       dev_err(scpsys->dev, "%pOF: failed to power on domain: 
%d\n", node, ret);
+                       goto err_unprepare_clocks;
+               }
        }
   
   	if (scpsys->domains[id]) {
@@ -395,7 +401,11 @@ generic_pm_domain *scpsys_add_one_domain(struct scpsys 
*scpsys, struct device_no
        pd->genpd.power_off = scpsys_power_off;
        pd->genpd.power_on = scpsys_power_on;
   
-	pm_genpd_init(&pd->genpd, NULL, false);
+       if (MTK_SCPD_CAPS(pd, MTK_SCPD_KEEP_DEFAULT_OFF))
+               pm_genpd_init(&pd->genpd, NULL, true);
+       else
+               pm_genpd_init(&pd->genpd, NULL, false);
+
        scpsys->domains[id] = &pd->genpd;
   
   	return scpsys->pd_data.domains[id];
@@ -478,7 +488,8 @@ static void scpsys_remove_one_domain(struct scpsys_domain 
*pd)
                        "failed to remove domain '%s' : %d - state may be 
inconsistent\n",
                        pd->genpd.name, ret);
   
-	scpsys_power_off(&pd->genpd);
+       if (!MTK_SCPD_CAPS(pd, MTK_SCPD_KEEP_DEFAULT_OFF))
+               scpsys_power_off(&pd->genpd);

OK, so you merged Weiyi's patches in this series :)

So same comment here: Does it really hurt if we turn-off a already turned-off
power domain? Or can we get rid of this check?


We do need this check here. If you try to turn-off this power domain,
you might make the clock or regulator reference count unbalanced.


Correct. Could we check via scpsys_domain_is_on() instead? I'd like to avoid 
MTK_SCPD_KEEP_DEFAULT_OFF use here.

Regards,
Matthias

Regards,
Matthias

   
   	clk_bulk_unprepare(pd->num_clks, pd->clks);
        clk_bulk_put(pd->num_clks, pd->clks);
diff --git a/drivers/soc/mediatek/mtk-pm-domains.h 
b/drivers/soc/mediatek/mtk-pm-domains.h
index 2ad213be84a5..0fa6a938b40c 100644
--- a/drivers/soc/mediatek/mtk-pm-domains.h
+++ b/drivers/soc/mediatek/mtk-pm-domains.h
@@ -6,6 +6,7 @@
   #define MTK_SCPD_ACTIVE_WAKEUP               BIT(0)
   #define MTK_SCPD_FWAIT_SRAM          BIT(1)
   #define MTK_SCPD_SRAM_ISO            BIT(2)
+#define MTK_SCPD_KEEP_DEFAULT_OFF      BIT(3)
   #define MTK_SCPD_CAPS(_scpd, _x)     ((_scpd)->data->caps & (_x))
   
   #define SPM_VDE_PWR_CON			0x0210