linux-kernel - Re: [RFC PATCH 1/5] mtd: cfi_cmdset_0002: Add support for polling status register

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <abff6b0f-af53-b712-c0fd-fe7c9fd83a56@cogentembedded.com>
Date:   Sat, 23 Feb 2019 21:44:10 +0300
From:   Sergei Shtylyov <sergei.shtylyov@...entembedded.com>
To:     "Vignesh R (by way of Boris Brezillon <bbrezillon@...nel.org>)" 
        <vigneshr@...com>, David Woodhouse <dwmw2@...radead.org>,
        Brian Norris <computersforpeace@...il.com>,
        Boris Brezillon <bbrezillon@...nel.org>,
        Marek Vasut <marek.vasut@...il.com>,
        Richard Weinberger <richard@....at>,
        Rob Herring <robh+dt@...nel.org>
Cc:     devicetree@...r.kernel.org, Arnd Bergmann <arnd@...db.de>,
        tudor.ambarus@...rochip.com,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        nsekhar@...com, linux-kernel@...r.kernel.org,
        linux-mtd@...ts.infradead.org, linux-arm-kernel@...ts.infradead.org
Subject: Re: [RFC PATCH 1/5] mtd: cfi_cmdset_0002: Add support for polling
 status register

On 02/19/2019 09:36 AM, Vignesh R (by way of Boris Brezillon <bbrezillon@...nel.org>) wrote:

> HyperFlash devices are compliant with CFI AMD/Fujitsu Extended Command
> Set(0x0002) for flash operations, therefore drivers/mtd/chips/cfi_cmdset_0002.c
> can be use as is. But these devices do not support DQ polling method of
> determining chip ready/good status. These flashes provide Status
> Register whose bits can be polled to know status of flash operation.
> 
> Cypress HyperFlash datasheet here[1], talks about CFI Amd/Fujitsu
> Extended Query version 1.5. Bit 0 of "Software Features supported" field
> of CFI Primary Vendor-Specific Extended Query table indicates
> presence/absence of status register and Bit 1 indicates whether or not
> DQ polling is supported. Using these bits, its possible to determine
> whether flash supports DQ polling or need to use Status Register.
> 
> Add support for polling status register to know device ready/status of
> erase/write operations when DQ polling is not supported.
> 
> [1] https://www.cypress.com/file/213346/download
> 
> Signed-off-by: Vignesh R <vigneshr@...com>

   Forgot about one thing: tags like S-o-b: need your full name,
cfr. Documentation/process/5.Posting.rst...

[...]

MBR, Sergei