summaryrefslogtreecommitdiff
path: root/drivers/phy/lantiq/phy-lantiq-rcu-usb2.c
diff options
context:
space:
mode:
authorMathias Kresin <dev@kresin.me>2021-01-07 23:49:01 +0100
committerVinod Koul <vkoul@kernel.org>2021-01-13 19:29:03 +0530
commit36acd5e24e3000691fb8d1ee31cf959cb1582d35 (patch)
treeab9a0c68b60acf293f0fac1ab727056867cbf50a /drivers/phy/lantiq/phy-lantiq-rcu-usb2.c
parentc188365402f65fbc1d1561aeaf4a20f09b0b4f22 (diff)
phy: lantiq: rcu-usb2: wait after clock enable
Commit 65dc2e725286 ("usb: dwc2: Update Core Reset programming flow.") revealed that the phy isn't ready immediately after enabling it's clocks. The dwc2_check_core_version() fails and the dwc2 usb driver errors out. Add a short delay to let the phy get up and running. There isn't any documentation how much time is required, the value was chosen based on tests. Signed-off-by: Mathias Kresin <dev@kresin.me> Acked-by: Hauke Mehrtens <hauke@hauke-m.de> Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Cc: <stable@vger.kernel.org> # v5.7+ Link: https://lore.kernel.org/r/20210107224901.2102479-1-dev@kresin.me Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/phy/lantiq/phy-lantiq-rcu-usb2.c')
-rw-r--r--drivers/phy/lantiq/phy-lantiq-rcu-usb2.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/phy/lantiq/phy-lantiq-rcu-usb2.c b/drivers/phy/lantiq/phy-lantiq-rcu-usb2.c
index a7d126192cf1..29d246ea24b4 100644
--- a/drivers/phy/lantiq/phy-lantiq-rcu-usb2.c
+++ b/drivers/phy/lantiq/phy-lantiq-rcu-usb2.c
@@ -124,8 +124,16 @@ static int ltq_rcu_usb2_phy_power_on(struct phy *phy)
reset_control_deassert(priv->phy_reset);
ret = clk_prepare_enable(priv->phy_gate_clk);
- if (ret)
+ if (ret) {
dev_err(dev, "failed to enable PHY gate\n");
+ return ret;
+ }
+
+ /*
+ * at least the xrx200 usb2 phy requires some extra time to be
+ * operational after enabling the clock
+ */
+ usleep_range(100, 200);
return ret;
}