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

From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Sricharan Ramabadhran <sricharan@codeaurora.org>
Cc: Manivannan Sadhasivam <mani@kernel.org>,
	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: Mon, 31 Jan 2022 10:52:20 +0100	[thread overview]
Message-ID: <20220131105220.167bacaf@xps13> (raw)
In-Reply-To: <a6fcc533-e7cd-7b55-4db0-cec80c07b46a@codeaurora.org>

Hi Sricharan,

sricharan@codeaurora.org wrote on Fri, 28 Jan 2022 23:20:04 +0530:

> 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 ?

Thanks for stepping up, it is really appreciated, good luck both for
the debugging.

Thanks,
Miquèl

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