Re: [PATCH v2 3/6] PCI: brcmstb: Do not turn off regulators if EP can wake up

2020-11-30 Thread Florian Fainelli



On 11/30/2020 1:11 PM, Jim Quinlan wrote:
> If any downstream device may wake up during S2/S3 suspend, we do not want
> to turn off its power when suspending.
> 
> Signed-off-by: Jim Quinlan 

Looks good to me, just one minor typo below:

> +enum {
> + TURN_OFF,   /* Turn egulators off, unless an EP is 
> wakeup-capable */

s/egulators/regulators/

> + TURN_OFF_ALWAYS,/* Turn Regulators off, no exceptions */
> + TURN_ON,/* Turn regulators on, unless 
> pcie->ep_wakeup_capable */

-- 
Florian


[PATCH v2 3/6] PCI: brcmstb: Do not turn off regulators if EP can wake up

2020-11-30 Thread Jim Quinlan
If any downstream device may wake up during S2/S3 suspend, we do not want
to turn off its power when suspending.

Signed-off-by: Jim Quinlan 
---
 drivers/pci/controller/pcie-brcmstb.c | 58 +++
 1 file changed, 51 insertions(+), 7 deletions(-)

diff --git a/drivers/pci/controller/pcie-brcmstb.c 
b/drivers/pci/controller/pcie-brcmstb.c
index 9d4ac42b3bee..cbdb315d4b2f 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -193,6 +193,7 @@ static inline void brcm_pcie_bridge_sw_init_set_7278(struct 
brcm_pcie *pcie, u32
 static inline void brcm_pcie_bridge_sw_init_set_generic(struct brcm_pcie 
*pcie, u32 val);
 static inline void brcm_pcie_perst_set_7278(struct brcm_pcie *pcie, u32 val);
 static inline void brcm_pcie_perst_set_generic(struct brcm_pcie *pcie, u32 
val);
+static bool brcm_pcie_link_up(struct brcm_pcie *pcie);
 
 enum {
RGR1_SW_INIT_1,
@@ -293,14 +294,57 @@ struct brcm_pcie {
void(*perst_set)(struct brcm_pcie *pcie, u32 val);
void(*bridge_sw_init_set)(struct brcm_pcie *pcie, 
u32 val);
struct regulator_bulk_data supplies[ARRAY_SIZE(ep_regulator_names)];
+   boolep_wakeup_capable;
 };
 
-static void brcm_set_regulators(struct brcm_pcie *pcie, bool on)
+static int pci_dev_may_wakeup(struct pci_dev *dev, void *data)
 {
+   bool *ret = data;
+
+   if (device_may_wakeup(>dev)) {
+   *ret = true;
+   dev_dbg(>dev, "disable cancelled for wake-up device\n");
+   }
+   return (int) *ret;
+}
+
+enum {
+   TURN_OFF,   /* Turn egulators off, unless an EP is 
wakeup-capable */
+   TURN_OFF_ALWAYS,/* Turn Regulators off, no exceptions */
+   TURN_ON,/* Turn regulators on, unless 
pcie->ep_wakeup_capable */
+};
+
+static void brcm_set_regulators(struct brcm_pcie *pcie, int how)
+{
+   struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
struct device *dev = pcie->dev;
int ret;
 
-   if (on)
+   if (how == TURN_ON) {
+   if (pcie->ep_wakeup_capable) {
+   /*
+* We are resuming from a suspend.  In the
+* previous suspend we did not disable the power
+* supplies, so there is no need to enable them
+* (and falsely increase their usage count).
+*/
+   pcie->ep_wakeup_capable = false;
+   return;
+   }
+   } else if (how == TURN_OFF) {
+   /*
+* If at least one device on this bus is enabled as a
+* wake-up source, do not turn off regulators.
+*/
+   pcie->ep_wakeup_capable = false;
+   if (bridge->bus && brcm_pcie_link_up(pcie)) {
+   pci_walk_bus(bridge->bus, pci_dev_may_wakeup, 
>ep_wakeup_capable);
+   if (pcie->ep_wakeup_capable)
+   return;
+   }
+   }
+
+   if (how == TURN_ON)
ret = regulator_bulk_enable(ARRAY_SIZE(ep_regulator_names),
pcie->supplies);
else
@@ -308,7 +352,7 @@ static void brcm_set_regulators(struct brcm_pcie *pcie, 
bool on)
 pcie->supplies);
if (ret)
dev_err(dev, "failed to %s EP regulators\n",
-   on ? "enable" : "disable");
+   how == TURN_ON ? "enable" : "disable");
 }
 
 /*
@@ -1161,7 +1205,7 @@ static int brcm_pcie_suspend(struct device *dev)
brcm_pcie_turn_off(pcie);
ret = brcm_phy_stop(pcie);
clk_disable_unprepare(pcie->clk);
-   brcm_set_regulators(pcie, false);
+   brcm_set_regulators(pcie, TURN_OFF);
 
return ret;
 }
@@ -1174,7 +1218,7 @@ static int brcm_pcie_resume(struct device *dev)
int ret;
 
base = pcie->base;
-   brcm_set_regulators(pcie, true);
+   brcm_set_regulators(pcie, TURN_ON);
clk_prepare_enable(pcie->clk);
 
ret = brcm_phy_start(pcie);
@@ -1213,7 +1257,7 @@ static void __brcm_pcie_remove(struct brcm_pcie *pcie)
brcm_phy_stop(pcie);
reset_control_assert(pcie->rescal);
clk_disable_unprepare(pcie->clk);
-   brcm_set_regulators(pcie, false);
+   brcm_set_regulators(pcie, TURN_OFF_ALWAYS);
 }
 
 static int brcm_pcie_remove(struct platform_device *pdev)
@@ -1308,7 +1352,7 @@ static int brcm_pcie_probe(struct platform_device *pdev)
return ret;
}
 
-   brcm_set_regulators(pcie, true);
+   brcm_set_regulators(pcie, TURN_ON);
ret = brcm_pcie_setup(pcie);
if (ret)
goto fail;
-- 
2.17.1



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