ar7: add NULL clock fix send upstream

Make the behaviour of clk_get_rate consistent with common clk's
clk_get_rate by accepting NULL clocks as parameter. Some device
drivers rely on this, and will cause an OOPS otherwise.

Signed-off-by: Mathias Kresin <dev@kresin.me>

1 files changed, 45 insertions, 0 deletions

diff --git a/target/linux/ar7/patches-3.18/101-MIPS-AR7-allow-NULL-clock-for-clk_get_rate.patch b/target/linux/ar7/patches-3.18/101-MIPS-AR7-allow-NULL-clock-for-clk_get_rate.patch
new file mode 100644
index 0000000000..74ac0d1482
--- /dev/null
+++ b/target/linux/ar7/patches-3.18/101-MIPS-AR7-allow-NULL-clock-for-clk_get_rate.patch
@@ -0,0 +1,45 @@
+From patchwork Tue Jul 18 10:17:26 2017
+Content-Type: text/plain; charset="utf-8"
+MIME-Version: 1.0
+Content-Transfer-Encoding: 7bit
+Subject: [5/9] MIPS: AR7: allow NULL clock for clk_get_rate
+X-Patchwork-Submitter: Jonas Gorski <jonas.gorski@gmail.com>
+X-Patchwork-Id: 16775
+Message-Id: <20170718101730.2541-6-jonas.gorski@gmail.com>
+To: unlisted-recipients:; (no To-header on input)
+Cc: Ralf Baechle <ralf@linux-mips.org>,
+ Paul Gortmaker <paul.gortmaker@windriver.com>,
+ James Hogan <james.hogan@imgtec.com>,
+ linux-mips@linux-mips.org, linux-kernel@vger.kernel.org
+Date: Tue, 18 Jul 2017 12:17:26 +0200
+From: Jonas Gorski <jonas.gorski@gmail.com>
+List-Id: linux-mips <linux-mips.eddie.linux-mips.org>
+
+Make the behaviour of clk_get_rate consistent with common clk's
+clk_get_rate by accepting NULL clocks as parameter. Some device
+drivers rely on this, and will cause an OOPS otherwise.
+
+Fixes: 780019ddf02f ("MIPS: AR7: Implement clock API")
+Cc: Ralf Baechle <ralf@linux-mips.org>
+Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
+Cc: James Hogan <james.hogan@imgtec.com>
+Cc: linux-mips@linux-mips.org
+Cc: linux-kernel@vger.kernel.org
+Reported-by: Mathias Kresin <dev@kresin.me>
+Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
+---
+ arch/mips/ar7/clock.c | 3 +++
+ 1 file changed, 3 insertions(+)
+
+--- a/arch/mips/ar7/clock.c
++++ b/arch/mips/ar7/clock.c
+@@ -430,6 +430,9 @@ EXPORT_SYMBOL(clk_disable);
+ 
+ unsigned long clk_get_rate(struct clk *clk)
+ {
++	if (!clk)
++		return 0;
++
+ 	return clk->rate;
+ }
+ EXPORT_SYMBOL(clk_get_rate);