I've noticed that when writing data to the modem the writes can time out
at some point eventually. Looks like kicking the modem idle GPIO every
600 ms instead of once a second fixes the issue. Note that this rate is
different from our runtime PM autosuspend rate MDM6600_MODEM_IDLE_DELAY_MS
that we still want to keep at 1 second, so let's add a separate define for
PHY_MDM6600_IDLE_KICK_MS.
Fixes: f7f50b2a7b05 ("phy: mapphone-mdm6600: Add runtime PM support for n_gsm on USB suspend")
Cc: Marcel Partap <mpartap@xxxxxxx>
Cc: Merlijn Wajer <merlijn@xxxxxxxxxx>
Cc: Michael Scott <hashcode0f@xxxxxxxxx>
Cc: NeKit <nekit1000@xxxxxxxxx>
Cc: Pavel Machek <pavel@xxxxxx>
Cc: Sebastian Reichel <sre@xxxxxxxxxx>
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
---
drivers/phy/motorola/phy-mapphone-mdm6600.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/phy/motorola/phy-mapphone-mdm6600.c b/drivers/phy/motorola/phy-mapphone-mdm6600.c
--- a/drivers/phy/motorola/phy-mapphone-mdm6600.c
+++ b/drivers/phy/motorola/phy-mapphone-mdm6600.c
@@ -20,6 +20,7 @@
#define PHY_MDM6600_PHY_DELAY_MS 4000 /* PHY enable 2.2s to 3.5s */
#define PHY_MDM6600_ENABLED_DELAY_MS 8000 /* 8s more total for MDM6600 */
+#define PHY_MDM6600_WAKE_KICK_MS 600 /* time on after GPIO toggle */
#define MDM6600_MODEM_IDLE_DELAY_MS 1000 /* modem after USB suspend */
#define MDM6600_MODEM_WAKE_DELAY_MS 200 /* modem response after idle */
@@ -525,8 +526,14 @@ static void phy_mdm6600_modem_wake(struct work_struct *work)
ddata = container_of(work, struct phy_mdm6600, modem_wake_work.work);
phy_mdm6600_wake_modem(ddata);
+
+ /*
+ * The modem does not always stay awake 1.2 seconds after toggling
+ * the wake GPIO, and sometimes it idles after about some 600 ms
+ * making writes time out.
+ */
schedule_delayed_work(&ddata->modem_wake_work,
- msecs_to_jiffies(MDM6600_MODEM_IDLE_DELAY_MS));
+ msecs_to_jiffies(PHY_MDM6600_WAKE_KICK_MS));
}
static int __maybe_unused phy_mdm6600_runtime_suspend(struct device *dev)
--
2.25.0
