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Message-ID: <3a75c310-1eb3-ebcf-82e0-99897e5e37c9@linaro.org>
Date:   Tue, 25 Jul 2023 22:11:11 +0200
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Subject: Re: [Patch RESEND 4/4] memory: tegra: make icc_set_bw return zero if
 BWMGR not supported
Content-Language: en-US
To:     Jon Hunter <jonathanh@nvidia.com>, Sumit Gupta <sumitg@nvidia.com>,
        treding@nvidia.com, linux-kernel@vger.kernel.org,
        linux-tegra@vger.kernel.org
Cc:     bbasu@nvidia.com, talho@nvidia.com
References: <20230621134400.23070-1-sumitg@nvidia.com>
 <20230621134400.23070-5-sumitg@nvidia.com>
 <df57e126-fe89-8a43-42aa-f0b4a5a404dc@nvidia.com>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <df57e126-fe89-8a43-42aa-f0b4a5a404dc@nvidia.com>
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Precedence: bulk

On 25/07/2023 20:29, Jon Hunter wrote:
> Hi Krzysztof,
> 
> On 21/06/2023 14:44, Sumit Gupta wrote:
>> Return zero from icc_set_bw() to MC client driver if MRQ_BWMGR_INT
>> is not supported by the BPMP-FW. Currently, 'EINVAL' is returned
>> which causes error message in client drivers even when the platform
>> doesn't support scaling.
>>
>> Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
>> ---
>>   drivers/memory/tegra/tegra234.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/memory/tegra/tegra234.c b/drivers/memory/tegra/tegra234.c
>> index bc73be7fe143..07aba301a173 100644
>> --- a/drivers/memory/tegra/tegra234.c
>> +++ b/drivers/memory/tegra/tegra234.c
>> @@ -951,7 +951,7 @@ static int tegra234_mc_icc_set(struct icc_node *src, struct icc_node *dst)
>>   		return 0;
>>   
>>   	if (!mc->bwmgr_mrq_supported)
>> -		return -EINVAL;
>> +		return 0;
>>   
>>   	if (!mc->bpmp) {
>>   		dev_err(mc->dev, "BPMP reference NULL\n");
>> @@ -998,7 +998,7 @@ static int tegra234_mc_icc_aggregate(struct icc_node *node, u32 tag, u32 avg_bw,
>>   	struct tegra_mc *mc = icc_provider_to_tegra_mc(p);
>>   
>>   	if (!mc->bwmgr_mrq_supported)
>> -		return -EINVAL;
>> +		return 0;
>>   
>>   	if (node->id == TEGRA_ICC_MC_CPU_CLUSTER0 ||
>>   	    node->id == TEGRA_ICC_MC_CPU_CLUSTER1 ||
> 
> 
> I have also found that this change is needed for Linux v6.5 in order to 
> work with current BPMP firmware. Without this patch PCIe does not work 
> on Tegra234. We should probably also add the following fixes tag for 
> this patch ...
> 
> Fixes: 9365bf006f53 ("PCI: tegra194: Add interconnect support in Tegra234")

Thank you, I moved the commit to fixes branch. I hope other patches do
not depend on the order (it was part of the patchset as 3/4 commit).

Since I re-shuffled everything, I will send pull for current RC
tomorrow, not today.

Best regards,
Krzysztof