linux-kernel - Re: [PATCH v6 4/4] soc: imx8m: change to use platform driver

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]

Date:   Wed, 25 Nov 2020 08:33:47 +0100
From:   Krzysztof Kozlowski <krzk@...nel.org>
To:     Adam Ford <aford173@...il.com>
Cc:     Alice Guo <alice.guo@....com>, Rob Herring <robh+dt@...nel.org>,
        Shawn Guo <shawnguo@...nel.org>,
        Sascha Hauer <s.hauer@...gutronix.de>,
        devicetree <devicetree@...r.kernel.org>,
        Peng Fan <peng.fan@....com>,
        NXP Linux Team <linux-imx@....com>,
        arm-soc <linux-arm-kernel@...ts.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v6 4/4] soc: imx8m: change to use platform driver

On Wed, 25 Nov 2020 at 01:44, Adam Ford <aford173@...il.com> wrote:
>
> On Mon, Nov 23, 2020 at 8:04 PM Alice Guo <alice.guo@....com> wrote:
> >
> > Directly reading ocotp register depends on that bootloader enables ocotp
> > clk, which is not always effective, so change to use nvmem API. Using
> > nvmem API requires to support driver defer probe and thus change
> > soc-imx8m.c to use platform driver.
> >
> > The other reason is that directly reading ocotp register causes kexec
> > kernel hang because the 1st kernel running will disable unused clks
> > after kernel boots up, and then ocotp clk will be disabled even if
> > bootloader enables it. When kexec kernel, ocotp clk needs to be enabled
> > before reading ocotp registers, and nvmem API with platform driver
> > supported can accomplish this.
> >
> > Signed-off-by: Alice Guo <alice.guo@....com>
> > ---
> >
> The patch reads V6, but the change log only shows V2.  Can you
> elaborate on what has changed between V2 and V6?
>
> adam
>
> > v2: remove the subject prefix "LF-2571-4"
> > v3: Keep the original way which uses device_initcall to read soc unique
> >     ID, and add the other way which uses module_platform_driver and
> >     nvmem API, so that it will not break the old version DTBs.
> > v4: delete "__maybe_unused"
> >     delete MODULE_DEVICE_TABLE(of, imx8m_soc_match);
> >     rename match table, "fsl,imx8mm/n/q/p" is actually a machine
> > compabile and "fsl,imx8mm/n/q/p-soc" is a compabile of soc@0
> >     delete "flag" and change to determine whether the pointer is NULL
> >     ues of_find_matching_node_and_match()
> >     delete of_match_ptr()
> > v5: add cleanup part "of_node_put"
> >     add note to explain that why device_initcall still exists
> > v6: none

Hi Adam,

It says up to v6, just in unnatural order... I was also surprised.

Best regards,
Krzysztof