linux-clk.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH] clk: vc5: Abort clock configuration without upstream clock
@ 2018-12-15  0:55 Marek Vasut
  2018-12-16  7:19 ` Laurent Pinchart
  2019-01-09 18:54 ` Stephen Boyd
  0 siblings, 2 replies; 7+ messages in thread
From: Marek Vasut @ 2018-12-15  0:55 UTC (permalink / raw)
  To: linux-clk
  Cc: linux-renesas-soc, Marek Vasut, Alexey Firago, Laurent Pinchart,
	Stephen Boyd

In case the upstream clock are not set, which can happen in case the
VC5 has no valid upstream clock, the $src variable is used uninited
by regmap_update_bits(). Check for this condition and return -EINVAL
in such case.

Note that in case the VC5 has no valid upstream clock, the VC5 can
not operate correctly. That is a hardware property of the VC5. The
internal oscilator present in some VC5 models is also considered
upstream clock.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Alexey Firago <alexey_firago@mentor.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: linux-renesas-soc@vger.kernel.org
---
NOTE: This is an updated version of:
      https://patchwork.kernel.org/patch/10731699/
---
 drivers/clk/clk-versaclock5.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/clk-versaclock5.c b/drivers/clk/clk-versaclock5.c
index 5b393e711e94..b10801506518 100644
--- a/drivers/clk/clk-versaclock5.c
+++ b/drivers/clk/clk-versaclock5.c
@@ -262,8 +262,10 @@ static int vc5_mux_set_parent(struct clk_hw *hw, u8 index)
 
 		if (vc5->clk_mux_ins == VC5_MUX_IN_XIN)
 			src = VC5_PRIM_SRC_SHDN_EN_XTAL;
-		if (vc5->clk_mux_ins == VC5_MUX_IN_CLKIN)
+		else if (vc5->clk_mux_ins == VC5_MUX_IN_CLKIN)
 			src = VC5_PRIM_SRC_SHDN_EN_CLKIN;
+		else
+			return -EINVAL;
 	}
 
 	return regmap_update_bits(vc5->regmap, VC5_PRIM_SRC_SHDN, mask, src);
-- 
2.18.0


^ permalink raw reply related	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2019-01-09 18:54 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-12-15  0:55 [PATCH] clk: vc5: Abort clock configuration without upstream clock Marek Vasut
2018-12-16  7:19 ` Laurent Pinchart
2018-12-16 17:14   ` Marek Vasut
2018-12-28 22:30     ` Stephen Boyd
2018-12-29 16:34       ` Laurent Pinchart
2019-01-09 18:49         ` Stephen Boyd
2019-01-09 18:54 ` Stephen Boyd

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).