Re: [PATCH] mtd: nand: raw: qcom_nandc: Don't clear_bam_transaction on READID

From: Sricharan Ramabadhran <sricharan@codeaurora.org>
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
Subject: Re: [PATCH] mtd: nand: raw: qcom_nandc: Don't clear_bam_transaction on READID
Date: Fri, 28 Jan 2022 23:20:04 +0530	[thread overview]
Message-ID: <a6fcc533-e7cd-7b55-4db0-cec80c07b46a@codeaurora.org> (raw)
In-Reply-To: <fc80a6e7-bd44-3b3e-fca2-1316a76d65f5@codeaurora.org>

Hi Konrad,

On 1/28/2022 9:55 AM, Sricharan Ramabadhran wrote:
> 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.
>
       While we could not reproduce this issue on our ipq boards (do not 
have a mdm9607 right now) and
        issue does not look any obvious.
       can you please give the debug logs that you did for the above 
stage by stage ?

   Regards,
       Sricharan