On 2020-11-23 14:03, Jerome Brunet wrote:
On Fri 20 Nov 2020 at 10:42, Marc Zyngier <maz@xxxxxxxxxx> wrote:
The HDMI driver request clocks early, but never disable them, leaving
the clocks on even when the driver is removed.
Fix it by slightly refactoring the clock code, and register a devm
action that will eventually disable/unprepare the enabled clocks.
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
---
drivers/gpu/drm/meson/meson_dw_hdmi.c | 43
++++++++++++++++++---------
1 file changed, 29 insertions(+), 14 deletions(-)
diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c
b/drivers/gpu/drm/meson/meson_dw_hdmi.c
index 7f8eea494147..29623b309cb1 100644
--- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
+++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
@@ -145,8 +145,6 @@ struct meson_dw_hdmi {
struct reset_control *hdmitx_apb;
struct reset_control *hdmitx_ctrl;
struct reset_control *hdmitx_phy;
- struct clk *hdmi_pclk;
- struct clk *venci_clk;
struct regulator *hdmi_supply;
u32 irq_stat;
struct dw_hdmi *hdmi;
@@ -946,6 +944,29 @@ static void meson_disable_regulator(void *data)
regulator_disable(data);
}
+static void meson_disable_clk(void *data)
+{
+ clk_disable_unprepare(data);
+}
+
+static int meson_enable_clk(struct device *dev, char *name)
+{
+ struct clk *clk;
+ int ret;
+
+ clk = devm_clk_get(dev, name);
+ if (IS_ERR(clk)) {
+ dev_err(dev, "Unable to get %s pclk\n", name);
+ return PTR_ERR(clk);
+ }
+
+ ret = clk_prepare_enable(clk);
+ if (!ret)
+ ret = devm_add_action_or_reset(dev, meson_disable_clk,
clk);
Thanks for fixing this Marc.
FYI, while it is fine to declare a function to disable the clocks, a
quick
cast may avoid it
devm_add_action_or_reset(dev, (void(*)(void *))clk_disable_unprepare,
clk);
While this works for now, a change to the clk_disable_unprepare()
prototype (such as adding a second argument) would now go completely
unnoticed (after all, you've cast the function, it *must* be correct,
right?), and someone would spend a few hours trying to track down memory
corruption or some other interesting results.
Yes, casting C functions can be hilarious.
I can see a few uses of this hack in the tree, and I have my pop-corn
ready.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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