15.01.2021 18:44, Thierry Reding пишет:
> 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 <pgwipe...@gmail.com>
>> Tested-by: Nicolas Chauvet <kwiz...@gmail.com>
>> Signed-off-by: Dmitry Osipenko <dig...@gmail.com>
>> ---
>> 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.
This is already fixed in v2. Good catch anyways, thanks.
> 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?
These are two independent changes. The previous patch fixed the missing
resets, this patch changes the hardware initialization logic.
