Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
In-Reply-To: <20190618092901.3bdd9f61@collabora.com>
References: <1555320234-15802-1-git-send-email-masonccyang@mxic.com.tw> <1555320234-15802-3-git-send-email-masonccyang@mxic.com.tw>
        <20190512151820.4f2dd9da@xps13> <OF074A1F06.5C1A58BE-ON482583FD.0031CD95-482583FD.003437AD@mxic.com.tw>
        <20190520142333.390091d5@xps13> <OFADC47344.0F9941B2-ON48258403.002336E3-48258403.003141F0@mxic.com.tw>
        <20190527144250.71908bd9@xps13> <OFE923A8E5.50375C30-ON48258409.0009AE1B-48258409.00119767@mxic.com.tw>
        <20190617143510.4ded5728@xps13> <OF1C1397B4.241DC339-ON4825841D.000482A2-4825841D.0007B67E@mxic.com.tw>
        <20190618081436.5d488320@collabora.com> <20190618092901.3bdd9f61@collabora.com>
To:     "Boris Brezillon" <boris.brezillon@collabora.com>
Cc:     bbrezillon@kernel.org, broonie@kernel.org,
        christophe.kerello@st.com, computersforpeace@gmail.com,
        devicetree@vger.kernel.org, dwmw2@infradead.org,
        geert@linux-m68k.org, juliensu@mxic.com.tw, lee.jones@linaro.org,
        liang.yang@amlogic.com, linux-kernel@vger.kernel.org,
        linux-mtd@lists.infradead.org, linux-spi@vger.kernel.org,
        marcel.ziswiler@toradex.com, marek.vasut@gmail.com,
        mark.rutland@arm.com, "Miquel Raynal" <miquel.raynal@bootlin.com>,
        paul.burton@mips.com, richard@nod.at, robh+dt@kernel.org,
        stefan@agner.ch, zhengxunli@mxic.com.tw
Subject: Re: [PATCH v3 2/4] mtd: rawnand: Add Macronix MX25F0A NAND controller
MIME-Version: 1.0
Message-ID: <OF5EAF94EB.AE31CF59-ON4825841E.002A2C38-4825841E.002C60BF@mxic.com.tw>
From:   masonccyang@mxic.com.tw
Date:   Wed, 19 Jun 2019 16:04:43 +0800
Content-Type: text/plain; charset="US-ASCII"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


Hi Boris,

> 
> Re: [PATCH v3 2/4] mtd: rawnand: Add Macronix MX25F0A NAND controller
> 
> On Tue, 18 Jun 2019 08:14:36 +0200
> Boris Brezillon <boris.brezillon@collabora.com> wrote:
> 
> > > > > > > 
> > > > > > > How to make all #CS keep high for NAND to enter 
> > > > > > > low-power standby mode if driver don't use 
"legacy.select_chip()" 
> > > ? 
> > > > > > 
> > > > > > See commit 02b4a52604a4 ("mtd: rawnand: Make ->select_chip()  
> > > optional 
> > > > > > when ->exec_op() is implemented") which states:
> > > > > > 
> > > > > >         "When [->select_chip() is] not implemented, the core 
is 
> > > assuming 
> > > > > >    the CS line is automatically asserted/deasserted by the 
driver 
> > > > > >    ->exec_op() implementation." 
> > > > > > 
> > > > > > Of course, the above is right only when the controller driver  
 
> > > supports 
> > > > > > the ->exec_op() interface. 
> > > > > 
> > > > > Currently, it seems that we will get the incorrect data and 
error
> > > > > operation due to CS in error toggling if CS line is controlled 
in 
> > > > > ->exec_op(). 
> 
> Oh, and please provide the modifications you added on top of this patch.
> Right now we're speculating on what you've done which is definitely not
> an efficient way to debug this sort of issues.

The patch is to add in beginning of ->exec_op() to control CS# low and 
before return from ->exec_op() to control CS# High.
i.e,.
static in mxic_nand_exec_op( )
{
 cs_to_low();


 cs_to_high();
 return;
}

But for nand_onfi_detect(), 
it calls nand_read_param_page_op() and then nand_read_data_op().
mxic_nand_exec_op() be called twice for nand_onfi_detect() and
driver will get incorrect ONFI parameter table data from 
nand_read_data_op().

thanks & best regards,
Mason


CONFIDENTIALITY NOTE:

This e-mail and any attachments may contain confidential information 
and/or personal data, which is protected by applicable laws. Please be 
reminded that duplication, disclosure, distribution, or use of this e-mail 
(and/or its attachments) or any part thereof is prohibited. If you receive 
this e-mail in error, please notify us immediately and delete this mail as 
well as its attachment(s) from your system. In addition, please be 
informed that collection, processing, and/or use of personal data is 
prohibited unless expressly permitted by personal data protection laws. 
Thank you for your attention and cooperation.

Macronix International Co., Ltd.

=====================================================================


============================================================================

CONFIDENTIALITY NOTE:

This e-mail and any attachments may contain confidential information and/or personal data, which is protected by applicable laws. Please be reminded that duplication, disclosure, distribution, or use of this e-mail (and/or its attachments) or any part thereof is prohibited. If you receive this e-mail in error, please notify us immediately and delete this mail as well as its attachment(s) from your system. In addition, please be informed that collection, processing, and/or use of personal data is prohibited unless expressly permitted by personal data protection laws. Thank you for your attention and cooperation.

Macronix International Co., Ltd.

=====================================================================