[PATCH AUTOSEL 5.1 27/70] net: stmmac: fix csr_clk can't be zero issue

[Sasha Levin]

From: Biao Huang <biao.huang@xxxxxxxxxxxx>

[ Upstream commit 5e7f7fc538d894b2d9aa41876b8dcf35f5fe11e6 ]

The specific clk_csr value can be zero, and
stmmac_clk is necessary for MDC clock which can be set dynamically.
So, change the condition from plat->clk_csr to plat->stmmac_clk to
fix clk_csr can't be zero issue.

Fixes: cd7201f477b9 ("stmmac: MDC clock dynamically based on the csr clock input")
Signed-off-by: Biao Huang <biao.huang@xxxxxxxxxxxx>
Acked-by: Alexandre TORGUE <alexandre.torgue@xxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c     | 6 +++---
 drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 5 ++++-
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 8cebc44108b2..635d88d82610 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -4380,10 +4380,10 @@ int stmmac_dvr_probe(struct device *device,
 	 * set the MDC clock dynamically according to the csr actual
 	 * clock input.
 	 */
-	if (!priv->plat->clk_csr)
-		stmmac_clk_csr_set(priv);
-	else
+	if (priv->plat->clk_csr >= 0)
 		priv->clk_csr = priv->plat->clk_csr;
+	else
+		stmmac_clk_csr_set(priv);
 
 	stmmac_check_pcs_mode(priv);
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index 3031f2bf15d6..f45bfbef97d0 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -408,7 +408,10 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
 	/* Default to phy auto-detection */
 	plat->phy_addr = -1;
 
-	/* Get clk_csr from device tree */
+	/* Default to get clk_csr from stmmac_clk_crs_set(),
+	 * or get clk_csr from device tree.
+	 */
+	plat->clk_csr = -1;
 	of_property_read_u32(np, "clk_csr", &plat->clk_csr);
 
 	/* "snps,phy-addr" is not a standard property. Mark it as deprecated
-- 
2.20.1