usb: ehci-hcd: fix call balance of clocks handling routines

If the clocks priv->iclk and priv->fclk were not enabled in ehci_hcd_sh_probe,
they should not be disabled in any path.

Conversely, if they was enabled in ehci_hcd_sh_probe, they must be disabled
in all error paths to ensure proper cleanup.

Found by Linux Verification Center (linuxtesting.org) with Klever.

Fixes: 63c8455 ("usb: ehci-hcd: Add support for SuperH EHCI.")
Cc: [email protected] # ff30bd6: sh: clk: Fix clk_enable() to return 0 on NULL clk
Signed-off-by: Vitalii Mordan <[email protected]>
Reviewed-by: Alan Stern <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: vmordan

drivers/usb/host/ehci-sh.c

@@ -119,8 +119,12 @@ static int ehci_hcd_sh_probe(struct platform_device *pdev)
 	if (IS_ERR(priv->iclk))
 		priv->iclk = NULL;
 
-	clk_enable(priv->fclk);
-	clk_enable(priv->iclk);
+	ret = clk_enable(priv->fclk);
+	if (ret)
+		goto fail_request_resource;
+	ret = clk_enable(priv->iclk);
+	if (ret)
+		goto fail_iclk;
 
 	ret = usb_add_hcd(hcd, irq, IRQF_SHARED);
 	if (ret != 0) {
@@ -136,6 +140,7 @@ static int ehci_hcd_sh_probe(struct platform_device *pdev)
 
 fail_add_hcd:
 	clk_disable(priv->iclk);
+fail_iclk:
 	clk_disable(priv->fclk);
 
 fail_request_resource: