Re: [PATCH 7/9] media: cedrus: Move IRQ maintainance to cedrus_dec_ops

From: Paul Kocialkowski
Date: Mon Jun 25 2018 - 11:38:19 EST


Hi,

On Wed, 2018-06-13 at 16:07 +0200, Maxime Ripard wrote:
> The IRQ handler up until now was hardcoding the use of the MPEG engine to
> read the interrupt status, clear it and disable the interrupts.
>
> Obviously, that won't work really well with the introduction of new codecs
> that use a separate engine with a separate register set.
>
> In order to make this more future proof, introduce new decodec operations
> to deal with the interrupt management. The only one missing is the one to
> enable the interrupts in the first place, but that's taken care of by the
> trigger hook for now.

Here's another comment about an issue I just figured out.

> Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxx>
> ---
> .../sunxi/cedrus/sunxi_cedrus_common.h | 9 +++++
> .../platform/sunxi/cedrus/sunxi_cedrus_hw.c | 21 ++++++------
> .../sunxi/cedrus/sunxi_cedrus_mpeg2.c | 33 +++++++++++++++++++
> 3 files changed, 53 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/media/platform/sunxi/cedrus/sunxi_cedrus_common.h b/drivers/media/platform/sunxi/cedrus/sunxi_cedrus_common.h
> index c2e2c92d103b..a2a507eb9fc9 100644
> --- a/drivers/media/platform/sunxi/cedrus/sunxi_cedrus_common.h
> +++ b/drivers/media/platform/sunxi/cedrus/sunxi_cedrus_common.h
> @@ -108,7 +108,16 @@ struct sunxi_cedrus_buffer *vb2_to_cedrus_buffer(const struct vb2_buffer *p)
> return vb2_v4l2_to_cedrus_buffer(to_vb2_v4l2_buffer(p));
> }
>
> +enum sunxi_cedrus_irq_status {
> + SUNXI_CEDRUS_IRQ_NONE,
> + SUNXI_CEDRUS_IRQ_ERROR,
> + SUNXI_CEDRUS_IRQ_OK,
> +};
> +
> struct sunxi_cedrus_dec_ops {
> + void (*irq_clear)(struct sunxi_cedrus_ctx *ctx);
> + void (*irq_disable)(struct sunxi_cedrus_ctx *ctx);
> + enum sunxi_cedrus_irq_status (*irq_status)(struct sunxi_cedrus_ctx *ctx);
> void (*setup)(struct sunxi_cedrus_ctx *ctx,
> struct sunxi_cedrus_run *run);
> void (*trigger)(struct sunxi_cedrus_ctx *ctx);
> diff --git a/drivers/media/platform/sunxi/cedrus/sunxi_cedrus_hw.c b/drivers/media/platform/sunxi/cedrus/sunxi_cedrus_hw.c
> index bb46a01214e0..6b97cbd2834e 100644
> --- a/drivers/media/platform/sunxi/cedrus/sunxi_cedrus_hw.c
> +++ b/drivers/media/platform/sunxi/cedrus/sunxi_cedrus_hw.c
> @@ -77,27 +77,28 @@ static irqreturn_t sunxi_cedrus_ve_irq(int irq, void *dev_id)
> struct sunxi_cedrus_ctx *ctx;
> struct sunxi_cedrus_buffer *src_buffer, *dst_buffer;
> struct vb2_v4l2_buffer *src_vb, *dst_vb;
> + enum sunxi_cedrus_irq_status status;
> unsigned long flags;
> - unsigned int value, status;
>
> spin_lock_irqsave(&dev->irq_lock, flags);
>
> - /* Disable MPEG interrupts and stop the MPEG engine */
> - value = sunxi_cedrus_read(dev, VE_MPEG_CTRL);
> - sunxi_cedrus_write(dev, value & (~0xf), VE_MPEG_CTRL);
> -
> - status = sunxi_cedrus_read(dev, VE_MPEG_STATUS);
> - sunxi_cedrus_write(dev, 0x0000c00f, VE_MPEG_STATUS);
> - sunxi_cedrus_engine_disable(dev);

This call was dropped from the code reorganization. What it intentional?

IMO, it should be brought back to the irq_disable ops for MPEG2 (and the
same probably applies to H264). Things still seem to work without it,
though, but there might be a difference in terms of standby VPU power
consumption.

Cheers,

Paul

--
Paul Kocialkowski, Bootlin (formerly Free Electrons)
Embedded Linux and kernel engineering
https://bootlin.com

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