Re: [PATCH v2] Docs: Fixes link to I2C specification

From: Randy Dunlap
Date: Sun Nov 21 2021 - 16:59:52 EST


On 11/21/21 9:46 AM, Deep Majumder wrote:
Randy Dunlap wrote:
On 11/18/21 10:14 PM, Deep Majumder wrote:
The link to the I2C specification is broken and is replaced in this
patch by one that points to Rev 6 (2014) of the specification.
Although `https://www.nxp.com"; hosts the Rev 7 (2021) of this
specification, it is behind a login-wall and thus cannot be used.

I don't quite get the "cannot be used" part.
I created a free login and downloaded this spec,
so yes, it's a hassle, but why can it not be used?

Perhaps a more appropriate wording would be "cannot be used as the only
source of the spec"? Because as I understand, many users may be
unwilling to sign up to a website just to download a spec sheet (if for
no other reason, for the fear of spam).

To be clear, I think that what you have added in the summary.rst
file is fine, but the commit message is too strong IMO.

I would just say something like
(or you could just add: cannot "easily" be used):

Although `https://www.nxp.com"; hosts the Rev 7 (2021) of this
specification, it is behind a login-wall and thus cannot easily be used,
while Rev 6 (2014) is readily available without requiring registration
and login.

Thus, an additional link has been added (which doesn't require a login)
and the NXP official docs link has been updated. The additional link is
not the Wayback Machine link since it seems that the PDF has not been
archived.

Signed-off-by: Deep Majumder <deep@xxxxxxxxxxx>
---
Documentation/i2c/summary.rst | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/Documentation/i2c/summary.rst b/Documentation/i2c/summary.rst
index 136c4e333be7..3395e2e46d9c 100644
--- a/Documentation/i2c/summary.rst
+++ b/Documentation/i2c/summary.rst
@@ -11,9 +11,11 @@ systems. Some systems use variants that don't meet branding requirements,
and so are not advertised as being I2C but come under different names,
e.g. TWI (Two Wire Interface), IIC.
-The official I2C specification is the `"I2C-bus specification and user
-manual" (UM10204) <https://www.nxp.com/docs/en/user-guide/UM10204.pdf>`_
-published by NXP Semiconductors.
+The official I2C specification (revision 7) is the `"I2C-bus specification and user
+manual" (UM10204) <https://www.nxp.com/webapp/Download?colCode=UM10204&location=null>`_
+published by NXP Semiconductors. However, you need to log-in to the site to
+access the PDF. An older version of the specification (revision 6) is available
+`here <https://www.pololu.com/file/0J435/UM10204.pdf>`_.
SMBus (System Management Bus) is based on the I2C protocol, and is mostly
a subset of I2C protocols and signaling. Many I2C devices will work on an

thanks.
--
~Randy