public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Christian Marangi <ansuelsmth@gmail.com>
To: Andrew Lunn <andrew@lunn.ch>
Cc: "David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Heiner Kallweit <hkallweit1@gmail.com>,
	Russell King <linux@armlinux.org.uk>,
	netdev@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, Robert Marko <robimarko@gmail.com>
Subject: Re: [net-next PATCH v2 1/2] net: phy: aquantia: add firmware load support
Date: Wed, 1 Nov 2023 17:41:54 +0100	[thread overview]
Message-ID: <65427fd4.df0a0220.28d26.1955@mx.google.com> (raw)
In-Reply-To: <34a0b76e-aa0e-4148-ba01-c3b4608f17f7@lunn.ch>

On Wed, Nov 01, 2023 at 05:32:29PM +0100, Andrew Lunn wrote:
> > > > +	for (pos = 0; pos < len; pos += min(sizeof(u32), len - pos)) {
> > > > +		u32 word = 0;
> > > > +
> > > > +		memcpy(&word, data + pos, min(sizeof(u32), len - pos));
> > > 
> > > Rather than do a memcpy, use the get_unaligned_ macros. They might map
> > > to a memcpy(), but some architectures can do unaligned accesses
> > > without problems.
> > > 
> > 
> > I don't think this is doable for this loop, think we would end up in
> > some funny situation where for the last run we have to copy less than
> > u32. (get_unaligned would always take u32 of data and that would end up
> > reading more than requested) Am I wrong?
> 
> Does it happen in practice that the last chunk is not 4 bytes?  Since
> this is firmware, its probably produced by some sort of linker, and
> they often round segments to words. Could you take a look at the
> firmware images you have access to and see if this is true?
>
> It could be we do need to keep with the memcpy, but it would be nice
> if we could limit it to words, at least until somebody has a firmware
> which is not word aligned.
>

There are plenty of firmware around so it can be checked by from what I
have, it looks like they are word aligned... Ok I will use the
get_unaligned and add a comment saying that we assume the iram and dram
section are always word aligned.

Is it ok?

-- 
	Ansuel

  reply	other threads:[~2023-11-01 16:42 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-01 12:36 [net-next PATCH v2 1/2] net: phy: aquantia: add firmware load support Christian Marangi
2023-11-01 12:36 ` [net-next PATCH v2 2/2] dt-bindings: Document bindings for Marvell Aquantia PHY Christian Marangi
2023-11-01 13:21   ` Andrew Lunn
2023-11-01 13:28   ` Rob Herring
2023-11-01 13:38     ` Rob Herring
2023-11-01 13:01 ` [net-next PATCH v2 1/2] net: phy: aquantia: add firmware load support Heiner Kallweit
2023-11-01 12:57   ` Christian Marangi
2023-11-01 16:57     ` Heiner Kallweit
2023-11-01 17:09       ` Christian Marangi
2023-11-01 13:13 ` Andrew Lunn
2023-11-01 15:51   ` Christian Marangi
2023-11-01 16:32     ` Andrew Lunn
2023-11-01 16:41       ` Christian Marangi [this message]
2023-11-01 16:54         ` Andrew Lunn
2023-11-01 17:08           ` Christian Marangi
2023-11-01 19:46             ` Andrew Lunn
2023-11-02 19:21 ` kernel test robot
2023-11-02 21:34 ` kernel test robot

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=65427fd4.df0a0220.28d26.1955@mx.google.com \
    --to=ansuelsmth@gmail.com \
    --cc=andrew@lunn.ch \
    --cc=conor+dt@kernel.org \
    --cc=davem@davemloft.net \
    --cc=devicetree@vger.kernel.org \
    --cc=edumazet@google.com \
    --cc=hkallweit1@gmail.com \
    --cc=krzysztof.kozlowski+dt@linaro.org \
    --cc=kuba@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@armlinux.org.uk \
    --cc=netdev@vger.kernel.org \
    --cc=pabeni@redhat.com \
    --cc=robh+dt@kernel.org \
    --cc=robimarko@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox