Hi Jacopo,
Thank you for the patch.
On Sat, Mar 12, 2022 at 04:25:05PM +0100, Jacopo Mondi wrote:
> The mipi_csis_device.powered flag only serves for the purpose of
> not accessing registers in mipi_csis_log_status() when the interface
> is not powered up.
>
> Instead of manually tracking the power state, rely on
> pm_runtime_get_if_in_use() and remove the flag.
>
> Signed-off-by: Jacopo Mondi <jacopo@xxxxxxxxxx>
> ---
> drivers/media/platform/imx/imx-mipi-csis.c | 18 ++++++++++--------
> 1 file changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/media/platform/imx/imx-mipi-csis.c b/drivers/media/platform/imx/imx-mipi-csis.c
> index fa00b36fc394..505dd373b40c 100644
> --- a/drivers/media/platform/imx/imx-mipi-csis.c
> +++ b/drivers/media/platform/imx/imx-mipi-csis.c
> @@ -327,10 +327,9 @@ struct mipi_csis_device {
> u32 hs_settle;
> u32 clk_settle;
>
> - struct mutex lock; /* Protect csis_fmt, format_mbus and powered */
> + struct mutex lock; /* Protect csis_fmt and format_mbus */
> const struct csis_pix_format *csis_fmt;
> struct v4l2_mbus_framefmt format_mbus[CSIS_PADS_NUM];
> - bool powered;
>
> spinlock_t slock; /* Protect events */
> struct mipi_csis_event events[MIPI_CSIS_NUM_EVENTS];
> @@ -1176,8 +1175,15 @@ static int mipi_csis_log_status(struct v4l2_subdev *sd)
>
> mutex_lock(&csis->lock);
> mipi_csis_log_counters(csis, true);
> - if (csis->debug.enable && csis->powered)
> - mipi_csis_dump_regs(csis);
> + if (!csis->debug.enable ||
> + !pm_runtime_get_if_in_use(csis->dev))
> + goto unlock;
> +
> + mipi_csis_dump_regs(csis);
> +
> + pm_runtime_put(csis->dev);
> +
> +unlock:
I like this change, but I think we can go one step further and drop the
lock here, as there's no powered field to access anymore:
struct mipi_csis_device *csis = sd_to_mipi_csis_device(sd);
mipi_csis_log_counters(csis, true);
if (csis->debug.enable && pm_runtime_get_if_in_use(csi->dev)) {
mipi_csis_dump_regs(csis);
pm_runtime_put(csis->dev);
}
return 0;
A third patch could then drop the lock from mipi_csis_runtime_suspend()
and mipi_csis_runtime_resume(). What do you think ?
> mutex_unlock(&csis->lock);
>
> return 0;
> @@ -1344,8 +1350,6 @@ static int __maybe_unused mipi_csis_runtime_suspend(struct device *dev)
>
> mipi_csis_clk_disable(csis);
>
> - csis->powered = false;
> -
> unlock:
> mutex_unlock(&csis->lock);
>
> @@ -1366,8 +1370,6 @@ static int __maybe_unused mipi_csis_runtime_resume(struct device *dev)
>
> mipi_csis_clk_enable(csis);
>
> - csis->powered = true;
> -
> unlock:
> mutex_unlock(&csis->lock);
>
--
Regards,
Laurent Pinchart
