[PATCH] host1x: hdmi: Make sure clock is enabled before dumping registers

[PATCH] host1x: hdmi: Make sure clock is enabled before dumping registers

[Mikko Perttunen]

The debugfs register dumping function did not enable the HDMI clock.
This led to a possible system hang when reading the debugfs entry
while no HDMI cable was connected to the system. This patch makes
sure that the clock is enabled during the read.

Signed-off-by: Mikko Perttunen <mperttunen-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
 drivers/gpu/host1x/drm/hdmi.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/host1x/drm/hdmi.c b/drivers/gpu/host1x/drm/hdmi.c
index 01097da..bf7f027 100644
--- a/drivers/gpu/host1x/drm/hdmi.c
+++ b/drivers/gpu/host1x/drm/hdmi.c
@@ -904,6 +904,11 @@ static int tegra_hdmi_show_regs(struct seq_file *s, void *data)
 {
 	struct drm_info_node *node = s->private;
 	struct tegra_hdmi *hdmi = node->info_ent->data;
+	int err;
+
+	err = clk_enable(hdmi->clk);
+	if (err)
+		return err;
 
 #define DUMP_REG(name)						\
 	seq_printf(s, "%-56s %#05x %08lx\n", #name, name,	\
@@ -1069,6 +1074,8 @@ static int tegra_hdmi_show_regs(struct seq_file *s, void *data)
 
 #undef DUMP_REG
 
+	clk_disable(hdmi->clk);
+
 	return 0;
 }
 
-- 
1.8.1.5

Re: [PATCH] host1x: hdmi: Make sure clock is enabled before dumping registers

[Thierry Reding]

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On Tue, Jul 30, 2013 at 11:35:03AM +0300, Mikko Perttunen wrote:
> The debugfs register dumping function did not enable the HDMI clock.
> This led to a possible system hang when reading the debugfs entry
> while no HDMI cable was connected to the system. This patch makes
> sure that the clock is enabled during the read.
> 
> Signed-off-by: Mikko Perttunen <mperttunen-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> ---
>  drivers/gpu/host1x/drm/hdmi.c | 7 +++++++
>  1 file changed, 7 insertions(+)

Applied, thanks.

Thierry

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