Re: [PATCH v1 04/17] media: camss: Make ISPIF subdevice optional

From: Bjorn Andersson
Date: Fri Jan 08 2021 - 14:08:10 EST


On Fri 08 Jan 06:04 CST 2021, Robert Foss wrote:

> This driver supports multiple architecture versions of the Qualcomm ISP.
> The CAMSS architecure which this driver is name after, and with the
> introduction of this series, the Titan architecture.
>
> The ISPIF is IP-block that is only present in the CAMSS architecture.

"is an IP-block"

> In order to support the Titan architecture, make the ISPIF an optional
> subdevice.
>
> Signed-off-by: Robert Foss <robert.foss@xxxxxxxxxx>
> ---
> .../media/platform/qcom/camss/camss-ispif.c | 144 ++++++++++--------
> .../media/platform/qcom/camss/camss-ispif.h | 3 +-
> drivers/media/platform/qcom/camss/camss.c | 113 +++++++++-----
> drivers/media/platform/qcom/camss/camss.h | 2 +-
> 4 files changed, 160 insertions(+), 102 deletions(-)
>
> diff --git a/drivers/media/platform/qcom/camss/camss-ispif.c b/drivers/media/platform/qcom/camss/camss-ispif.c
[..]
> -int msm_ispif_subdev_init(struct ispif_device *ispif,
> +int msm_ispif_subdev_init(struct camss *camss,
> const struct resources_ispif *res)
> {
> - struct device *dev = to_device(ispif);
> - struct platform_device *pdev = to_platform_device(dev);
> + struct ispif_device *ispif = camss->ispif;
> + struct platform_device *pdev = to_platform_device(camss->dev);

It seems like several of the changes in this function is replacing
dev with camss->dev. If you retained a struct device *dev = camss->dev;
you would avoid this.

> struct resource *r;
> int i;
> int ret;
>
> + if (res == NULL && ispif == NULL)

Afaict this function is called conditional on camss->ispif != NULL, and
I don't see anything that would cause res to becomes NULL if is hasn't
been before this change.

So I think this check is unnecessary?

> + return 0;
> +
> + ispif->camss = camss;
> +
> /* Number of ISPIF lines - same as number of CSID hardware modules */
> - if (to_camss(ispif)->version == CAMSS_8x16)
> + if (camss->version == CAMSS_8x16)
> ispif->line_num = 2;
> - else if (to_camss(ispif)->version == CAMSS_8x96 ||
> - to_camss(ispif)->version == CAMSS_660)
> + else if (camss->version == CAMSS_8x96 ||
> + camss->version == CAMSS_660)
> ispif->line_num = 4;
> else
> return -EINVAL;
>
> - ispif->line = devm_kcalloc(dev, ispif->line_num, sizeof(*ispif->line),
> - GFP_KERNEL);
> + ispif->line = devm_kcalloc(camss->dev, ispif->line_num,
> + sizeof(*ispif->line), GFP_KERNEL);
> if (!ispif->line)
> return -ENOMEM;
>
[..]
> @@ -1393,6 +1410,9 @@ void msm_ispif_unregister_entities(struct ispif_device *ispif)
> {
> int i;
>
> + if (!ispif)
> + return;

I like this, but later in the patch you make the calls to this function
conditional on ispif != NULL. You should only need one of the checks.

Regards,
Bjorn