On Tue, Jan 12, 2021 at 03:58:34PM +0300, Dmitry Osipenko wrote:
> Assert hardware reset before clocks are enabled and then de-assert it
> after clocks are enabled. This brings hardware into a predictable state
> and removes relying on implicit de-assertion of resets which is done by
> the clk driver.
>
> Tested-by: Peter Geis <pgwipeout@xxxxxxxxx>
> Tested-by: Nicolas Chauvet <kwizart@xxxxxxxxx>
> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
> ---
> sound/soc/tegra/tegra30_ahub.c | 33 ++++++++++++++++-----------------
> sound/soc/tegra/tegra30_ahub.h | 1 +
> 2 files changed, 17 insertions(+), 17 deletions(-)
>
> diff --git a/sound/soc/tegra/tegra30_ahub.c b/sound/soc/tegra/tegra30_ahub.c
> index 4dbb58f7ea36..246cf6a373a1 100644
> --- a/sound/soc/tegra/tegra30_ahub.c
> +++ b/sound/soc/tegra/tegra30_ahub.c
> @@ -65,10 +65,20 @@ static int tegra30_ahub_runtime_resume(struct device *dev)
> {
> int ret;
>
> + ret = reset_control_assert(ahub->reset);
> + if (ret)
> + return ret;
> +
> ret = clk_bulk_prepare_enable(ahub->nclocks, ahub->clocks);
> if (ret)
> return ret;
>
> + ret = reset_control_reset(ahub->reset);
> + if (ret) {
> + clk_bulk_disable_unprepare(ahub->nclocks, ahub->clocks);
> + return ret;
> + }
> +
> regcache_cache_only(ahub->regmap_apbif, false);
> regcache_cache_only(ahub->regmap_ahub, false);
>
> @@ -462,7 +472,6 @@ static int tegra30_ahub_probe(struct platform_device *pdev)
> {
> const struct of_device_id *match;
> const struct tegra30_ahub_soc_data *soc_data;
> - struct reset_control *rst;
> struct resource *res0;
> void __iomem *regs_apbif, *regs_ahub;
> int ret = 0;
> @@ -475,22 +484,6 @@ static int tegra30_ahub_probe(struct platform_device *pdev)
> return -EINVAL;
> soc_data = match->data;
>
> - /*
> - * The AHUB hosts a register bus: the "configlink". For this to
> - * operate correctly, all devices on this bus must be out of reset.
> - * Ensure that here.
> - */
> - rst = of_reset_control_array_get_exclusive(pdev->dev.of_node);
> - if (IS_ERR(rst)) {
> - dev_err(&pdev->dev, "Can't get reset: %p\n", rst);
> - return PTR_ERR(rst);
> - }
> -
> - ret = reset_control_deassert(rst);
> - reset_control_put(rst);
> - if (ret)
> - return ret;
> -
> ahub = devm_kzalloc(&pdev->dev, sizeof(struct tegra30_ahub),
> GFP_KERNEL);
> if (!ahub)
> @@ -507,6 +500,12 @@ static int tegra30_ahub_probe(struct platform_device *pdev)
> if (ret)
> return ret;
>
> + ahub->reset = devm_reset_control_array_get_exclusive(&pdev->dev);
> + if (IS_ERR(ahub->reset)) {
> + dev_err(&pdev->dev, "Can't get reset: %p\n", ahub->reset);
I didn't notice that the prior patch already introduced this, but I'd
prefer for this to either be %pe so that the symbolic error name is
printed, or %ld with PTR_ERR(ahub->reset) to format this in a more
standard way that can be more easily grepped for and parsed.
It also seems like the prior patch that converts this to use
of_reset_control_array_get_exclusive() is a bit pointless now. Why not
just move to this directly instead?
Thierry
Attachment:
signature.asc
Description: PGP signature
