[PATCH 6.1 317/609] phy: zynqmp: Allow variation in refclk rate

6.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Sean Anderson <[email protected]>

[ Upstream commit 76009ee76e05e30e29aade02e788aebe9ce9ffd2 ]

Due to limited available frequency ratios, the reference clock rate may
not be exactly the same as the required rate. Allow a small (100 ppm)
deviation.

Signed-off-by: Sean Anderson <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Vinod Koul <[email protected]>
Stable-dep-of: e4779e2a16d6 ("phy: zynqmp: fix clock error handling in xpsgtr_phy_init()")
Signed-off-by: Sasha Levin <[email protected]>
---
 drivers/phy/xilinx/phy-zynqmp.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/phy/xilinx/phy-zynqmp.c b/drivers/phy/xilinx/phy-zynqmp.c
index cc36fb7616ae4..00ceeca2a395f 100644
--- a/drivers/phy/xilinx/phy-zynqmp.c
+++ b/drivers/phy/xilinx/phy-zynqmp.c
@@ -958,7 +958,10 @@ static int xpsgtr_get_ref_clocks(struct xpsgtr_dev *gtr_dev)
 		rate = clk_get_rate(clk);
 
 		for (i = 0 ; i < ARRAY_SIZE(ssc_lookup); i++) {
-			if (rate == ssc_lookup[i].refclk_rate) {
+			/* Allow an error of 100 ppm */
+			unsigned long error = ssc_lookup[i].refclk_rate / 10000;
+
+			if (abs(rate - ssc_lookup[i].refclk_rate) < error) {
 				gtr_dev->refclk_sscs[refclk] = &ssc_lookup[i];
 				break;
 			}
-- 
2.53.0