phy: zynqmp: Only wait for PLL lock "primary" instances

For PCIe and DisplayPort, the phy instance represents the controller's
logical lane. Wait for the instance 0 phy's PLL to lock as other
instances will never lock. We do this in xpsgtr_wait_pll_lock so callers
don't have to determine the correct lane themselves.

The original comment is wrong about cumulative wait times. Since we are
just polling a bit, all subsequent waiters will finish immediately.

Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Link: https://lore.kernel.org/r/20240628205540.3098010-4-sean.anderson@linux.dev
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/phy/xilinx/phy-zynqmp.c b/drivers/phy/xilinx/phy-zynqmp.c
index a1cf32024efbfb5f7b0f3294d8dee32a78a672d8..4d697e11d8eb7b6c46e9b4152d7d9e5771aca4ca 100644 (file)
--- a/drivers/phy/xilinx/phy-zynqmp.c
+++ b/drivers/phy/xilinx/phy-zynqmp.c
@@ -294,10 +294,30 @@ static int xpsgtr_wait_pll_lock(struct phy *phy)
        struct xpsgtr_phy *gtr_phy = phy_get_drvdata(phy);
        struct xpsgtr_dev *gtr_dev = gtr_phy->dev;
        unsigned int timeout = TIMEOUT_US;
+       u8 protocol = gtr_phy->protocol;
        int ret;
 
        dev_dbg(gtr_dev->dev, "Waiting for PLL lock\n");
 
+       /*
+        * For DP and PCIe, only the instance 0 PLL is used. Switch to that phy
+        * so we wait on the right PLL.
+        */
+       if ((protocol == ICM_PROTOCOL_DP || protocol == ICM_PROTOCOL_PCIE) &&
+           gtr_phy->instance) {
+               int i;
+
+               for (i = 0; i < NUM_LANES; i++) {
+                       gtr_phy = &gtr_dev->phys[i];
+
+                       if (gtr_phy->protocol == protocol && !gtr_phy->instance)
+                               goto got_phy;
+               }
+
+               return -EBUSY;
+       }
+
+got_phy:
        while (1) {
                u32 reg = xpsgtr_read_phy(gtr_phy, L0_PLL_STATUS_READ_1);
 
@@ -625,15 +645,7 @@ static int xpsgtr_phy_power_on(struct phy *phy)
        /* Skip initialization if not required. */
        if (!xpsgtr_phy_init_required(gtr_phy))
                return ret;
-       /*
-        * Wait for the PLL to lock. For DP, only wait on DP0 to avoid
-        * cumulating waits for both lanes. The user is expected to initialize
-        * lane 0 last.
-        */
-       if (gtr_phy->protocol != ICM_PROTOCOL_DP || !gtr_phy->instance)
-               ret = xpsgtr_wait_pll_lock(phy);
-
-       return ret;
+       return xpsgtr_wait_pll_lock(phy);
 }
 
 static int xpsgtr_phy_configure(struct phy *phy, union phy_configure_opts *opts)