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Subject: Re: [PATCH] mtd: nand: raw: qcom_nandc: Don't clear_bam_transaction
 on READID
To:     Miquel Raynal <miquel.raynal@bootlin.com>,
        Manivannan Sadhasivam <mani@kernel.org>
Cc:     Konrad Dybcio <konrad.dybcio@somainline.org>,
        ~postmarketos/upstreaming@lists.sr.ht, martin.botka@somainline.org,
        angelogioacchino.delregno@somainline.org,
        marijn.suijten@somainline.org, jamipkettunen@somainline.org,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        linux-mtd@lists.infradead.org, linux-arm-msm@vger.kernel.org,
        linux-kernel@vger.kernel.org, mdalam@codeaurora.org
References: <20220113184427.2259509-1-konrad.dybcio@somainline.org>
 <20220114082718.32a2fc83@xps13> <20220126111613.3ab0021e@xps13>
 <20220126103316.GA212068@thinkpad> <20220126114200.4cc3c21b@xps13>
From:   Sricharan Ramabadhran <sricharan@codeaurora.org>
Message-ID: <fc80a6e7-bd44-3b3e-fca2-1316a76d65f5@codeaurora.org>
Date:   Fri, 28 Jan 2022 09:55:01 +0530
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Hi Miquel,

On 1/26/2022 4:12 PM, Miquel Raynal wrote:
> Hi Mani,
>
> mani@kernel.org wrote on Wed, 26 Jan 2022 16:03:16 +0530:
>
>> On Wed, Jan 26, 2022 at 11:16:13AM +0100, Miquel Raynal wrote:
>>> Hello,
>>>
>>> miquel.raynal@bootlin.com wrote on Fri, 14 Jan 2022 08:27:18 +0100:
>>>    
>>>> Hi Konrad,
>>>>
>>>> konrad.dybcio@somainline.org wrote on Thu, 13 Jan 2022 19:44:26 +0100:
>>>>    
>>>>> While I have absolutely 0 idea why and how, running clear_bam_transaction
>>>>> when READID is issued makes the DMA totally clog up and refuse to function
>>>>> at all on mdm9607. In fact, it is so bad that all the data gets garbled
>>>>> and after a short while in the nand probe flow, the CPU decides that
>>>>> sepuku is the only option.
>>>>>
>>>>> Removing _READID from the if condition makes it work like a charm, I can
>>>>> read data and mount partitions without a problem.
>>>>>
>>>>> Signed-off-by: Konrad Dybcio <konrad.dybcio@somainline.org>
>>>>> ---
>>>>> This is totally just an observation which took me an inhumane amount of
>>>>> debug prints to find.. perhaps there's a better reason behind this, but
>>>>> I can't seem to find any answers.. Therefore, this is a BIG RFC!
>>>> I'm adding two people from codeaurora who worked a lot on this driver.
>>>> Hopefully they will have an idea :)
>>> Sadre, I've spent a significant amount of time reviewing your patches,
>>> now it's your turn to not take a month to answer to your peers
>>> proposals.
>>>
>>> Please help reviewing this patch.
>>>    
>> Sorry. I was hoping that Qcom folks would chime in as I don't have any idea
>> about the mdm9607 platform. It could be that the mail server migration from
>> codeaurora to quicinc put a barrier here.
>>
>> Let me ping them internally.
> Oh, ok, I didn't know. Thanks!

    Sorry Miquel, somehow we did not get this email in our inbox.
    Thanks to Mani for pinging us, we will test this up today and get back.

Regards,
    Sricharan