Re: [RFT net] net: ipa: fix u32_replace_bits by u32p_xxx version

[Alex Elder <elder@linaro.org>]

On 9/9/20 7:02 AM, Vadym Kochan wrote:
> Hi Alex,
> 
> On Wed, Sep 09, 2020 at 06:53:17AM -0500, Alex Elder wrote:
>> On 9/8/20 9:32 AM, Vadym Kochan wrote:
>>> Looks like u32p_replace_bits() should be used instead of
>>> u32_replace_bits() which does not modifies the value but returns the
>>> modified version.
>>>
>>> Fixes: 2b9feef2b6c2 ("soc: qcom: ipa: filter and routing tables")
>>> Signed-off-by: Vadym Kochan <vadym.kochan@plvision.eu>
>>
>> You are correct!  Thank you for finding this.
>>
>> Your fix is good, and I have now tested it and verified it
>> works as desired.
>>
>> FYI, this is currently used only for the SDM845 platform.  It turns
>> out the register values (route and filter hash config) that are read
>> and intended to be updated always have value 0, so (fortunately) your
>> change has no effect there.
>>
> 
> I had such assumption that probably it works without the fix.
> 
>> Nevertheless, you have fixed this bug and I appreciate it.
>>
>> Reviewed-by: Alex Elder <elder@linaro.org>
>>
> 
> My understanding is that I need to re-submit this as an official patch
> without RFT/RFC prefix and with your reviewed tag ?

I hope David will accept it with my review, but if not maybe
he can answer your question.  Let's give him a chance to do
that, and if he hasn't responded within a day or two then
go ahead and send an updated version 2.

					-Alex

> Regards,
> Vadym Kochan
> 
>>> ---
>>> Found it while grepping of u32_replace_bits() usage and
>>> replaced it w/o testing.
>>>
>>>  drivers/net/ipa/ipa_table.c | 4 ++--
>>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/net/ipa/ipa_table.c b/drivers/net/ipa/ipa_table.c
>>> index 2098ca2f2c90..b3790aa952a1 100644
>>> --- a/drivers/net/ipa/ipa_table.c
>>> +++ b/drivers/net/ipa/ipa_table.c
>>> @@ -521,7 +521,7 @@ static void ipa_filter_tuple_zero(struct ipa_endpoint *endpoint)
>>>  	val = ioread32(endpoint->ipa->reg_virt + offset);
>>>  
>>>  	/* Zero all filter-related fields, preserving the rest */
>>> -	u32_replace_bits(val, 0, IPA_REG_ENDP_FILTER_HASH_MSK_ALL);
>>> +	u32p_replace_bits(&val, 0, IPA_REG_ENDP_FILTER_HASH_MSK_ALL);
>>>  
>>>  	iowrite32(val, endpoint->ipa->reg_virt + offset);
>>>  }
>>> @@ -573,7 +573,7 @@ static void ipa_route_tuple_zero(struct ipa *ipa, u32 route_id)
>>>  	val = ioread32(ipa->reg_virt + offset);
>>>  
>>>  	/* Zero all route-related fields, preserving the rest */
>>> -	u32_replace_bits(val, 0, IPA_REG_ENDP_ROUTER_HASH_MSK_ALL);
>>> +	u32p_replace_bits(&val, 0, IPA_REG_ENDP_ROUTER_HASH_MSK_ALL);
>>>  
>>>  	iowrite32(val, ipa->reg_virt + offset);
>>>  }
>>>
>>