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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Proofpoint-GUID: 6IEkpBYMH2iiu__xYuN0ey_mF1c9de82 X-Authority-Analysis: v=2.4 cv=D7J37PRj c=1 sm=1 tr=0 ts=69ef8729 cx=c_pps a=JbAStetqSzwMeJznSMzCyw==:117 a=gOEeR9iKwsj33Yj5oN/cWg==:17 a=IkcTkHD0fZMA:10 a=A5OVakUREuEA:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=u7WPNUs3qKkmUXheDGA7:22 a=DJpcGTmdVt4CTyJn9g5Z:22 a=EUspDBNiAAAA:8 a=XYAwZIGsAAAA:8 a=r1NGz-dz-RQI755fX4UA:9 a=QEXdDO2ut3YA:10 a=uxP6HrT_eTzRwkO_Te1X:22 a=E8ToXWR_bxluHZ7gmE-Z:22 X-Proofpoint-ORIG-GUID: 6IEkpBYMH2iiu__xYuN0ey_mF1c9de82 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNDI3MDE3MCBTYWx0ZWRfX2mC8evmAxyCZ mGUUgXX7K9kM/JAN4RjQiMVVXvSSViIKLBWFD+AvtD/QRL2+VZsyEU1ahjW8UsmxTcl8NfUKmCw khJ7+0HWN7ZP+HPkVingE6GkbweO2/QiFF4WfjlHpf3daaxE0hdRyE83fAtYA0f76Z4VBtM0tEK yL8uws7i06WvmlcmZww1g30bmY3b/elqfOuZE/vl7xkpaNsCMViYwhCTG0pCzKCGNK0HYSGv/QA Jo733Ayer7FNwedwb97pjj9QdB/nKLxnq/R6jbfdL053shzx08N8EvrqPviqlWGhXyRelVTh13c VHXuOdwfkl0rsYl7y9bXgHoNlPHPh+kQQJimO69qXHECZe8rDobdVmvkp2klqdhKqPNHm/lUjsb r0Tz8x/Kxv0uB1IMTYo+B97qaWiNZ3zPaks2Kjjc4Tg3M7YV9lyFLzwz+UEbyP22x8AbSd8YsoB G6LGleYp7CKjqXr96TQ== X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49 definitions=2026-04-27_04,2026-04-21_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 bulkscore=0 phishscore=0 lowpriorityscore=0 spamscore=0 priorityscore=1501 suspectscore=0 clxscore=1015 adultscore=0 malwarescore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2604200000 definitions=main-2604270170 On 27/04/2026 16:37, Rob Herring wrote: > On Wed, Apr 15, 2026 at 03:46:41PM +0100, Conor Dooley wrote: >> On Wed, Apr 15, 2026 at 10:21:14AM +0200, Krzysztof Kozlowski wrote: >>> Extend the guidelines when to use fallback compatibles to cover to >>> common review responses. Devices are most likely compatible and should >>> use fallbacks when having: >>> >>> 1. Compatible programming interface, meaning one is a subset, and Linux >>> device drivers can use the subset to correctly match/bind and still >>> operate with the subset features. >>> >>> 2. Device variant discovery through some means, like registers. >>> >>> Devices are incompatible and fallback is not suitable when that >>> fallback cannot be used by the drivers to match/bind. >>> >>> Signed-off-by: Krzysztof Kozlowski >>> --- >>> Documentation/devicetree/bindings/writing-bindings.rst | 7 ++++++- >>> 1 file changed, 6 insertions(+), 1 deletion(-) >>> >>> diff --git a/Documentation/devicetree/bindings/writing-bindings.rst b/Documentation/devicetree/bindings/writing-bindings.rst >>> index 667816dd7d50..03e29e2d50af 100644 >>> --- a/Documentation/devicetree/bindings/writing-bindings.rst >>> +++ b/Documentation/devicetree/bindings/writing-bindings.rst >>> @@ -53,7 +53,12 @@ Properties >>> - DON'T use wildcards or device-family names in compatible strings. >>> >>> - DO use fallback compatibles when devices are the same as or a superset of >>> - prior implementations. >>> + prior implementations. Fallback compatibles are applicable especially >>> + when sharing a programming interface or when able to discover the >>> + variants. >>> + >>> + - DON'T add fake fallback compatibles when software cannot use such to match >>> + and bind to a device, and still operate correctly. >>> >>> - DO add new compatibles in case there are new features or bugs. >> >> Acked-by: Conor Dooley >> >> - DO use the commit message explain why devices that may appear >> compatible in a diff (e.g. no differences in property use) but >> are not compatible, are not compatible. > > Can you respin with Conor's addition. Ack Best regards, Krzysztof