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Date:   Wed, 26 Jan 2022 11:16:13 +0100
From:   Miquel Raynal <miquel.raynal@bootlin.com>
To:     Konrad Dybcio <konrad.dybcio@somainline.org>
Cc:     ~postmarketos/upstreaming@lists.sr.ht, martin.botka@somainline.org,
        angelogioacchino.delregno@somainline.org,
        marijn.suijten@somainline.org, jamipkettunen@somainline.org,
        Manivannan Sadhasivam <mani@kernel.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,
        sricharan@codeaurora.org
Subject: Re: [PATCH] mtd: nand: raw: qcom_nandc: Don't clear_bam_transaction
 on READID
Message-ID: <20220126111613.3ab0021e@xps13>
In-Reply-To: <20220114082718.32a2fc83@xps13>
References: <20220113184427.2259509-1-konrad.dybcio@somainline.org>
        <20220114082718.32a2fc83@xps13>
Organization: Bootlin
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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.

BTW why is this driver still using cmdfund? It should have been
migrated to ->exec_op() a long time ago.

Thanks,
Miquèl