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From: Richard Weinberger <richard@nod.at>
To: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Kamal Dasu <kdasu.kdev@gmail.com>,
	linux-mtd <linux-mtd@lists.infradead.org>,
	bcm-kernel-feedback-list <bcm-kernel-feedback-list@broadcom.com>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	David Woodhouse <dwmw2@infradead.org>,
	Brian Norris <computersforpeace@gmail.com>,
	Marek Vasut <marek.vasut@gmail.com>,
	Vignesh Raghavendra <vigneshr@ti.com>
Subject: Re: [PATCH] mtd: set mtd partition panic write flag
Date: Wed, 6 Nov 2019 00:03:42 +0100 (CET)	[thread overview]
Message-ID: <1718371158.75883.1572995022606.JavaMail.zimbra@nod.at> (raw)
In-Reply-To: <20191105200344.1e8c3eab@xps13>

----- Ursprüngliche Mail -----
> Von: "Miquel Raynal" <miquel.raynal@bootlin.com>
> An: "Kamal Dasu" <kdasu.kdev@gmail.com>
> CC: "linux-mtd" <linux-mtd@lists.infradead.org>, "bcm-kernel-feedback-list" <bcm-kernel-feedback-list@broadcom.com>,
> "linux-kernel" <linux-kernel@vger.kernel.org>, "David Woodhouse" <dwmw2@infradead.org>, "Brian Norris"
> <computersforpeace@gmail.com>, "Marek Vasut" <marek.vasut@gmail.com>, "richard" <richard@nod.at>, "Vignesh Raghavendra"
> <vigneshr@ti.com>
> Gesendet: Dienstag, 5. November 2019 20:03:44
> Betreff: Re: [PATCH] mtd: set mtd partition panic write flag

> Hi Kamal,
> 
> Richard, something to look into below :)

I'm still recovering from a bad cold. So my brain is not fully working ;)
 
> Kamal Dasu <kdasu.kdev@gmail.com> wrote on Mon, 21 Oct 2019 15:32:52
> -0400:
> 
>> Check mtd panic write flag and set the mtd partition panic
>> write flag so that low level drivers can use it to take
>> required action to ensure oops data gets written to assigned
>> mtd partition.
> 
> I feel there is something wrong with the current implementation
> regarding partitions but I am not sure this is the right fix. Is this
> something you detected with some kind of static checker or did you
> actually experience an issue?
> 
> In the commit log you say "check mtd (I suppose you mean the
> master) panic write flag and set the mtd partition panic write flag"
> which makes sense, but in reality my understanding is that you do the
> opposite: you check mtd->oops_panic_write which is the partitions'
> structure, and set part->parent->oops_panic_write which is the master's
> flag.

IIUC the problem happens when you run mtdoops on a mtd partition.
The the flag is only set for the partition instead for the master.

So the right fix would be setting the parent's oops_panic_write in
mtd_panic_write().
Then we don't have to touch mtdpart.c

Thanks,
//richard

WARNING: multiple messages have this Message-ID (diff)
From: Richard Weinberger <richard@nod.at>
To: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Vignesh Raghavendra <vigneshr@ti.com>,
	Kamal Dasu <kdasu.kdev@gmail.com>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	Marek Vasut <marek.vasut@gmail.com>,
	bcm-kernel-feedback-list <bcm-kernel-feedback-list@broadcom.com>,
	linux-mtd <linux-mtd@lists.infradead.org>,
	Brian Norris <computersforpeace@gmail.com>,
	David Woodhouse <dwmw2@infradead.org>
Subject: Re: [PATCH] mtd: set mtd partition panic write flag
Date: Wed, 6 Nov 2019 00:03:42 +0100 (CET)	[thread overview]
Message-ID: <1718371158.75883.1572995022606.JavaMail.zimbra@nod.at> (raw)
In-Reply-To: <20191105200344.1e8c3eab@xps13>

----- Ursprüngliche Mail -----
> Von: "Miquel Raynal" <miquel.raynal@bootlin.com>
> An: "Kamal Dasu" <kdasu.kdev@gmail.com>
> CC: "linux-mtd" <linux-mtd@lists.infradead.org>, "bcm-kernel-feedback-list" <bcm-kernel-feedback-list@broadcom.com>,
> "linux-kernel" <linux-kernel@vger.kernel.org>, "David Woodhouse" <dwmw2@infradead.org>, "Brian Norris"
> <computersforpeace@gmail.com>, "Marek Vasut" <marek.vasut@gmail.com>, "richard" <richard@nod.at>, "Vignesh Raghavendra"
> <vigneshr@ti.com>
> Gesendet: Dienstag, 5. November 2019 20:03:44
> Betreff: Re: [PATCH] mtd: set mtd partition panic write flag

> Hi Kamal,
> 
> Richard, something to look into below :)

I'm still recovering from a bad cold. So my brain is not fully working ;)
 
> Kamal Dasu <kdasu.kdev@gmail.com> wrote on Mon, 21 Oct 2019 15:32:52
> -0400:
> 
>> Check mtd panic write flag and set the mtd partition panic
>> write flag so that low level drivers can use it to take
>> required action to ensure oops data gets written to assigned
>> mtd partition.
> 
> I feel there is something wrong with the current implementation
> regarding partitions but I am not sure this is the right fix. Is this
> something you detected with some kind of static checker or did you
> actually experience an issue?
> 
> In the commit log you say "check mtd (I suppose you mean the
> master) panic write flag and set the mtd partition panic write flag"
> which makes sense, but in reality my understanding is that you do the
> opposite: you check mtd->oops_panic_write which is the partitions'
> structure, and set part->parent->oops_panic_write which is the master's
> flag.

IIUC the problem happens when you run mtdoops on a mtd partition.
The the flag is only set for the partition instead for the master.

So the right fix would be setting the parent's oops_panic_write in
mtd_panic_write().
Then we don't have to touch mtdpart.c

Thanks,
//richard

______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

  reply	other threads:[~2019-11-05 23:03 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-21 19:32 [PATCH] mtd: set mtd partition panic write flag Kamal Dasu
2019-10-21 19:32 ` Kamal Dasu
2019-11-05 19:03 ` Miquel Raynal
2019-11-05 19:03   ` Miquel Raynal
2019-11-05 23:03   ` Richard Weinberger [this message]
2019-11-05 23:03     ` Richard Weinberger
2019-11-11 20:35     ` Kamal Dasu
2019-11-11 20:35       ` Kamal Dasu
2020-01-09 15:03     ` Miquel Raynal
2020-01-09 15:03       ` Miquel Raynal
2020-01-09 15:25       ` Kamal Dasu
2020-01-09 15:25         ` Kamal Dasu
2020-01-09 17:28         ` Miquel Raynal
2020-01-09 17:28           ` Miquel Raynal
2020-05-02 18:08           ` Miquel Raynal
2020-05-02 18:08             ` Miquel Raynal
2020-05-04 15:20             ` Kamal Dasu
2020-05-04 15:20               ` Kamal Dasu
2020-05-04 17:29               ` Miquel Raynal
2020-05-04 17:29                 ` Miquel Raynal

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