Re: [PATCH 05/10] ARM: bcm2835: Add the mailbox power channel driver.

Arnd Bergmann
2015-03-02T21:09:00Z

On Monday 02 March 2015 12:54:39 Eric Anholt wrote:
> +/*
> + * Submits a set of concatenated tags to the VPU firmware through the
> + * mailbox power interface.
> + *
> + * The buffer header and the ending tag are added by this function and
> + * don't need to be supplied, just the actual tags for your operation.
> + * See struct bcm_mbox_power_tag_header for the per-tag structure.
> + */
> +static int bcm_mbox_set_power(uint32_t power_enables)
> +{
> + int ret;
> +
> + reinit_completion(&mbox_power->c);
> + ret = mbox_send_message(mbox_power->chan,
> + (void *)(power_enables << BCM_MBOX_DATA_SHIFT));
> + if (ret >= 0)
> + wait_for_completion(&mbox_power->c);
> +
> + return ret;
>

Please don't abuse the pointer argument to send an integer.

Instead, pass a pointer to the data argument as intended. As this
is a recurring problem, we may want to add a different interface
to pass fixed-length inline data, maybe

mbox_send_message_u32(struct mbox_chan *chan, u32 msg);

and possibly add a length argument to the existing mbox_send_message.

Arnd