Re: [PATCH v2 1/5] media: atmel_isc: Add spin lock for clock enable ops

From: Sakari Ailus
Date: Wed Sep 27 2017 - 03:16:36 EST


Hi Wenyou,

On subject:

s/_/-/

On Mon, Sep 18, 2017 at 02:39:21PM +0800, Wenyou Yang wrote:
> Add the spin lock for the clock enable and disable operations.
>
> Signed-off-by: Wenyou Yang <wenyou.yang@xxxxxxxxxxxxx>
> ---
>
> Changes in v2: None
>
> drivers/media/platform/atmel/atmel-isc.c | 14 +++++++++++++-
> 1 file changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/platform/atmel/atmel-isc.c b/drivers/media/platform/atmel/atmel-isc.c
> index 2f8e345d297e..78114193af4c 100644
> --- a/drivers/media/platform/atmel/atmel-isc.c
> +++ b/drivers/media/platform/atmel/atmel-isc.c
> @@ -65,6 +65,7 @@ struct isc_clk {
> struct clk_hw hw;
> struct clk *clk;
> struct regmap *regmap;
> + spinlock_t *lock;

Can this work? I don't see lock being assigned anywhere. Did you mean

spinlock_t lock;

?

> u8 id;
> u8 parent_id;
> u32 div;
> @@ -312,26 +313,37 @@ static int isc_clk_enable(struct clk_hw *hw)
> struct isc_clk *isc_clk = to_isc_clk(hw);
> u32 id = isc_clk->id;
> struct regmap *regmap = isc_clk->regmap;
> + unsigned long flags;
> + unsigned int status;
>
> dev_dbg(isc_clk->dev, "ISC CLK: %s, div = %d, parent id = %d\n",
> __func__, isc_clk->div, isc_clk->parent_id);
>
> + spin_lock_irqsave(isc_clk->lock, flags);
> regmap_update_bits(regmap, ISC_CLKCFG,
> ISC_CLKCFG_DIV_MASK(id) | ISC_CLKCFG_SEL_MASK(id),
> (isc_clk->div << ISC_CLKCFG_DIV_SHIFT(id)) |
> (isc_clk->parent_id << ISC_CLKCFG_SEL_SHIFT(id)));
>
> regmap_write(regmap, ISC_CLKEN, ISC_CLK(id));
> + spin_unlock_irqrestore(isc_clk->lock, flags);
>
> - return 0;
> + regmap_read(regmap, ISC_CLKSR, &status);
> + if (status & ISC_CLK(id))
> + return 0;
> + else
> + return -EINVAL;
> }
>
> static void isc_clk_disable(struct clk_hw *hw)
> {
> struct isc_clk *isc_clk = to_isc_clk(hw);
> u32 id = isc_clk->id;
> + unsigned long flags;
>
> + spin_lock_irqsave(isc_clk->lock, flags);
> regmap_write(isc_clk->regmap, ISC_CLKDIS, ISC_CLK(id));
> + spin_unlock_irqrestore(isc_clk->lock, flags);
> }
>
> static int isc_clk_is_enabled(struct clk_hw *hw)

--
Regards,

Sakari Ailus
e-mail: sakari.ailus@xxxxxx