On Tue, 15 Apr 2025 13:21:25 +0200 Matthias Schiffer <matthias.schiffer@xxxxxxxxxxxxxxx> wrote: > On Tue, 2025-04-15 at 13:15 +0200, Maxime Chevallier wrote: > > On Tue, 15 Apr 2025 12:18:04 +0200 > > Matthias Schiffer <matthias.schiffer@xxxxxxxxxxxxxxx> wrote: > > > > > Historially, the RGMII PHY modes specified in Device Trees have been > > ^^^^^^^^^^^ > > Historically > > > used inconsistently, often referring to the usage of delays on the PHY > > > side rather than describing the board; many drivers still implement this > > > incorrectly. > > > > > > Require a comment in Devices Trees using these modes (usually mentioning > > > that the delay is relalized on the PCB), so we can avoid adding more > > > incorrect uses (or will at least notice which drivers still need to be > > > fixed). > > > > > > Suggested-by: Andrew Lunn <andrew@xxxxxxx> > > > Signed-off-by: Matthias Schiffer <matthias.schiffer@xxxxxxxxxxxxxxx> > > > --- > > > Documentation/dev-tools/checkpatch.rst | 9 +++++++++ > > > scripts/checkpatch.pl | 11 +++++++++++ > > > 2 files changed, 20 insertions(+) > > > > > > diff --git a/Documentation/dev-tools/checkpatch.rst b/Documentation/dev-tools/checkpatch.rst > > > index abb3ff6820766..8692d3bc155f1 100644 > > > --- a/Documentation/dev-tools/checkpatch.rst > > > +++ b/Documentation/dev-tools/checkpatch.rst > > > @@ -513,6 +513,15 @@ Comments > > > > > > See: https://lore.kernel.org/lkml/20131006222342.GT19510@leaf/ > > > > > > + **UNCOMMENTED_RGMII_MODE** > > > + Historially, the RGMII PHY modes specified in Device Trees have been > > ^^^^^^^^^^^ > > Historically > > > + used inconsistently, often referring to the usage of delays on the PHY > > > + side rather than describing the board. > > > + > > > + PHY modes "rgmii", "rgmii-rxid" and "rgmii-txid" modes require the clock > > > + signal to be delayed on the PCB; this unusual configuration should be > > > + described in a comment. If they are not (meaning that the delay is realized > > > + internally in the MAC or PHY), "rgmii-id" is the correct PHY mode. > > > > > > Commit message > > > -------------- > > > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl > > > index 784912f570e9d..57fcbd4b63ede 100755 > > > --- a/scripts/checkpatch.pl > > > +++ b/scripts/checkpatch.pl > > > @@ -3735,6 +3735,17 @@ sub process { > > > } > > > } > > > > > > +# Check for RGMII phy-mode with delay on PCB > > > + if ($realfile =~ /\.dtsi?$/ && $line =~ /^\+\s*(phy-mode|phy-connection-type)\s*=\s*"/ && > > > + !ctx_has_comment($first_line, $linenr)) { > > > + my $prop = $1; > > > + my $mode = get_quoted_string($line, $rawline); > > > + if ($mode =~ /^"rgmii(?:|-rxid|-txid)"$/) { > > > + CHK("UNCOMMENTED_RGMII_MODE", > > > + "$prop $mode without comment -- delays on the PCB should be described, otherwise use \"rgmii-id\"\n" . $herecurr); > > > + } > > > + } > > > + > > > > My Perl-fu isn't good enough for me to review this properly... I think > > though that Andrew mentioned something along the lines of 'Comment > > should include PCB somewhere', but I don't know if this is easily > > doable with checkpatch though. > > > > Maxime > > I think it can be done using ctx_locate_comment instead of ctx_has_comment, but > I decided against it - requiring to have a comment at all should be sufficient > to make people think about the used mode, and a comment with a bad explanation > would hopefully be caught during review. True, and having looked at other stuff in checkpatch, it looks like there's no other example of rules expecting a specific word in a comment. So besides the typo above, I'm OK with this patch :) Maxime
