Re: [PATCHv2 03/11] soc: ti: omap-prm: poll for reset complete during de-assert

[Tero Kristo <t-kristo@ti.com>]

On 29/08/2019 16:14, Philipp Zabel wrote:
> Hi Tero,
> 
> On Wed, 2019-08-28 at 10:19 +0300, Tero Kristo wrote:
>> Poll for reset completion status during de-assertion of reset, otherwise
>> the IP in question might be accessed before it has left reset properly.
>>
>> Signed-off-by: Tero Kristo <t-kristo@ti.com>
>> ---
>>   drivers/soc/ti/omap_prm.c | 20 ++++++++++++++++++++
>>   1 file changed, 20 insertions(+)
>>
>> diff --git a/drivers/soc/ti/omap_prm.c b/drivers/soc/ti/omap_prm.c
>> index fd5c431f8736..afeb70761b27 100644
>> --- a/drivers/soc/ti/omap_prm.c
>> +++ b/drivers/soc/ti/omap_prm.c
>> @@ -127,6 +127,7 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev,
>>   	u32 v;
>>   	int st_bit;
>>   	bool has_rstst;
>> +	int timeout = 0;
>>   
>>   	if (!_is_valid_reset(reset, id))
>>   		return -EINVAL;
>> @@ -153,6 +154,25 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev,
>>   	v &= ~(1 << id);
>>   	writel_relaxed(v, reset->prm->base + reset->prm->data->rstctrl);
>>   
>> +	if (!has_rstst)
>> +		return 0;
>> +
>> +	/* wait for the status to be set */
>> +	while (1) {
>> +		v = readl_relaxed(reset->prm->base + reset->prm->data->rstst);
>> +		v &= 1 << st_bit;
>> +		if (v)
>> +			break;
>> +		timeout++;
>> +		if (timeout > OMAP_RESET_MAX_WAIT) {
>> +			pr_err("%s: timedout waiting for %s:%lu\n", __func__,
>> +			       dev_name(rcdev->dev), id);
>> +			return -EBUSY;
>> +		}
>> +
>> +		udelay(1);
>> +	}
> 
> This looks like you could use
> 
> 	readl_relaxed_poll_timeout(_atomic)

Yeah true, let me change that.

-Tero
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