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

JIRA: https://issues.redhat.com/browse/RHEL-78828

commit 97264ea
Author: Vitalii Mordan <mordan@ispras.ru>
Date: Thu, 21 Nov 2024 14:47:00 +0300

  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: stable@vger.kernel.org # ff30bd6: sh: clk: Fix clk_enable() to return 0 on NULL clk
  Signed-off-by: Vitalii Mordan <mordan@ispras.ru>
  Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
  Link: https://lore.kernel.org/r/20241121114700.2100520-1-mordan@ispras.ru
  Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Desnes Nunes <desnesn@redhat.com>

Author: Desnes Nunes

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: