[PATCH v6 3/4] phy: ti-pipe3: Fix EPROBE_DEFER handling for clock resources

[Hongling Zeng]

ti_pipe3_get_clk() has two issues with -EPROBE_DEFER error handling:

1. When devm_clk_get() for sysclk fails, the function returns -EINVAL
   instead of propagating the actual error code. This masks -EPROBE_DEFER
   to -EINVAL, breaking the probe deferral mechanism and causing permanent
   driver initialization failure on systems with non-deterministic probe
   ordering.

2. For SATA PHY refclk, the function ignores all errors to support older
   DTBs missing the refclk property. However, this incorrectly ignores
   -EPROBE_DEFER as well, causing the driver to proceed without waiting
   for the clock provider to become available.

Fix both issues:
- Return PTR_ERR(phy->sys_clk) instead of -EINVAL to propagate all
  error codes including -EPROBE_DEFER
- Use devm_clk_get_optional() for SATA refclk to handle optional
  clocks while propagating -EPROBE_DEFER and other errors

Fixes: a70143bbef6b ("drivers: phy: usb3/pipe3: Adapt pipe3 driver to Generic PHY Framework")
Fixes: 7f33912d2978 ("phy: ti-pipe3: Fix SATA across suspend/resume")
Signed-off-by: Hongling Zeng <zenghongling at kylinos.cn>

---
Change in v4:
 -Merge refclk leak fix and EPROBE_DEFER fix into a single patch
 -Use devm_clk_get_optional() for SATA refclk
 -Drop manual -ENOENT handling
 -Ensure error paths are fully symmetric
---
Change in v5:
 -Add Fix ignored clock enable return value in init patch
---
Change in v6:
 -Fix all clock leak paths comprehensively:
 -PCIe syscon update failure path
 -SATA DPLL lock check path (also fix incorrect return logic)
 -SATA errata path in ti_pipe3_exit()
---
 drivers/phy/ti/phy-ti-pipe3.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/phy/ti/phy-ti-pipe3.c b/drivers/phy/ti/phy-ti-pipe3.c
index 2d36fe4c4218..9ec228c2a940 100644
--- a/drivers/phy/ti/phy-ti-pipe3.c
+++ b/drivers/phy/ti/phy-ti-pipe3.c
@@ -608,14 +608,20 @@ static int ti_pipe3_get_clk(struct ti_pipe3 *phy)
 	struct clk *clk;
 	struct device *dev = phy->dev;
 
-	phy->refclk = devm_clk_get(dev, "refclk");
+	/*
+	 * refclk is optional for SATA PHY to support older DTBs, but
+	 * required for other modes. Use devm_clk_get_optional() for SATA
+	 * which returns NULL for -ENOENT, allowing us to propagate all
+	 * other errors including -EPROBE_DEFER.
+	 */
+	if (phy->mode == PIPE3_MODE_SATA)
+		phy->refclk = devm_clk_get_optional(dev, "refclk");
+	else
+		phy->refclk = devm_clk_get(dev, "refclk");
+
 	if (IS_ERR(phy->refclk)) {
 		dev_err(dev, "unable to get refclk\n");
-		/* older DTBs have missing refclk in SATA PHY
-		 * so don't bail out in case of SATA PHY.
-		 */
-		if (phy->mode != PIPE3_MODE_SATA)
-			return PTR_ERR(phy->refclk);
+		return PTR_ERR(phy->refclk);
 	}
 
 	if (phy->mode != PIPE3_MODE_SATA) {
@@ -632,7 +638,7 @@ static int ti_pipe3_get_clk(struct ti_pipe3 *phy)
 		phy->sys_clk = devm_clk_get(dev, "sysclk");
 		if (IS_ERR(phy->sys_clk)) {
 			dev_err(dev, "unable to get sysclk\n");
-			return -EINVAL;
+			return PTR_ERR(phy->sys_clk);
 		}
 	}
 
-- 
2.25.1