From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-03.galae.net (smtpout-03.galae.net [185.246.85.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 56DE4397E8D for ; Thu, 4 Jun 2026 07:28:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.246.85.4 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780558117; cv=none; b=TvFC36cvAgI52vKd/A5BOn6IZ62tP3h4izUCLherst3b/CC9ZdU7fLmFSQpp8hXDT6rg89iZA02EqxCBAFO2lFz7pL92m8hatERe5yquzinJM0kpSnJ/qJxTihuTtfSP8TRvPUPBuTzad9ur4LEVZSINBynxm4Mrlj7mc3lUE6Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780558117; c=relaxed/simple; bh=N3FYJH0Na6n0IvoTQRLh82Jz6KolB+LqBxz9CxTQz94=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=hVn1U90s0bLKaQMaihAWuIfF5TfGBl+ghYsM9HVoSkrGc12JSWHGjmAbPZREG/G8cUFBaxrQkKlBWaohl8GlSmSfE91LEfRjRow8Cw4lgZAbAFLha+friT3ipKGjFXk6sgx00PbwdZPeIWZQqIy2T86f9T6FdaMyheNs/XW9SDc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=dMdEvho4; arc=none smtp.client-ip=185.246.85.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="dMdEvho4" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-03.galae.net (Postfix) with ESMTPS id 0CA894E40505; Thu, 4 Jun 2026 07:28:35 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id D1AD45FEF7; Thu, 4 Jun 2026 07:28:34 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 456D4106A1395; Thu, 4 Jun 2026 09:28:30 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1780558113; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=N3FYJH0Na6n0IvoTQRLh82Jz6KolB+LqBxz9CxTQz94=; b=dMdEvho48GdK6q0uOpDC6L/F42yGqD6zMP7d3/DWu1YG2xKyP41yvy8Ls25V2u26R+R6mw Ll8krPj+hKwrsNoDpMuj6gqO1kVC+8FcKaFegFHR63i2FrG67i9r6U8z8dRxVmTqI13OQA NX2h+kXu06x/b60IjPtlrP5XOA2ctB2D1VbJrrCyv+UqChU71mwngXqLITHqc0KydvPqmL cbnLanbbpXYvPYaGr97h/TB2WNJjKlhWQgdfl1rKPz0RdVX3ZtPAm+UGv36GIz2XtI32oW GfA4m28YL1V5ltQLEpS1UbcvdoPPjQ7phMVD5k/7mEnV5IG5CEJjfLEZJXDryg== From: Miquel Raynal To: Rob Herring Cc: Santhosh Kumar K , broonie@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, richard@nod.at, vigneshr@ti.com, pratyush@kernel.org, mwalle@kernel.org, takahiro.kuwano@infineon.com, linux-spi@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, praneeth@ti.com, u-kumar1@ti.com, a-dutta@ti.com Subject: Re: [PATCH v3 02/13] spi: dt-bindings: cdns,qspi-nor: add PHY tuning pattern partition property In-Reply-To: (Rob Herring's message of "Wed, 3 Jun 2026 12:38:46 -0500") References: <20260527175527.2247679-1-s-k6@ti.com> <20260527175527.2247679-3-s-k6@ti.com> <20260602164945.GA475455-robh@kernel.org> <87zf1by5oc.fsf@bootlin.com> User-Agent: mu4e 1.12.7; emacs 30.2 Date: Thu, 04 Jun 2026 09:28:29 +0200 Message-ID: <87cxy6ydb6.fsf@bootlin.com> Precedence: bulk X-Mailing-List: linux-spi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Last-TLS-Session-Version: TLSv1.3 On 03/06/2026 at 12:38:46 -05, Rob Herring wrote: > On Wed, Jun 3, 2026 at 11:01=E2=80=AFAM Miquel Raynal wrote: >> >> Hello, >> >> On 02/06/2026 at 11:49:45 -05, Rob Herring wrote: >> >> > On Wed, May 27, 2026 at 11:25:16PM +0530, Santhosh Kumar K wrote: >> >> PHY tuning requires a known data pattern to be readable from flash. >> >> When no partition is explicitly identified, the controller must search >> >> all available partitions to locate the pattern by label, which adds >> >> overhead and relies on label naming conventions outside the >> >> controller's control. >> > >> > I agree 'label' is not the best choice. Software should not care what >> > 'label' contains. It should really be 'compatible' instead. >> >> But compatible does not seem relevant in this case, right? We are just >> flagging the location of "some useful data for the controller". > > compatible is what tells us what a region contains and how to use it. > That seems exactly what we need to define here. We usually talk about "programming model" when it comes to compatible, here we just need to point at an offset which is in no way different (from a hardware standpoint) than the other offsets. I honestly feel like a phandle property would be simpler, also because compatibles in MTD are already quite complex to manage and I would prefer not to add more complexity into the parsing logic. >> >> Add cdns,phy-pattern-partition, a phandle property that allows the DT >> >> author to directly reference the flash partition holding the PHY tuni= ng >> >> pattern. The controller uses this partition during calibration, avoid= ing >> >> the partition search entirely. >> > >> > Do you have any data that this approach being "direct" is faster? In >> > fact, it might be worse. Instead of searching just the limited number = of >> > partition subnodes, you now search the entire tree for a matching >> > phandle value. We do have phandle caching, so that might save you >> > here. >> >> True, but besides performance considerations, I personally do not find >> elegant using a partition name/label, but maybe that's just personal >> taste :-) > > I agree. That's true for all the partition nodes with only node name > or label to go on. We should fix that at the source. However, you > already have to support using label, Hum, no? There is downstream support for labels in TI kernels, but we explicitly asked Santhosh to drop it for mainline inclusion. His commit message may be a bit misleading on this regard because he is mentioning labels like if we were already using them, despite the fact that we are not. > so anything else is supporting a > 2nd way whether it is compatible or a phandle property. Is it really > worth it here? > > Rob Thanks, Miqu=C3=A8l From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DEABDCD6E4A for ; Thu, 4 Jun 2026 07:28:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:References :In-Reply-To:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=gEdGMc+jrd780pPtW0r2m3EzDS/hFKFXpTm7bKbXjT4=; b=vqdTsDBtc7trK+ kslnOaqYP6FJq7T/CTjHvhP5DbNr/M8Yykdjr2b+VlGa+qcFPGP8izoImSKkzGW8os4TD04X4msee 8A9qS2ugZRKeCxJ75x6i96SyG5ieL7NSiGWfZEgDvFYsAHDNVT/JvcEozEgZrOND9hfGVO7R44i2X 6YaKbIvj/Ynt7ASg6Qhyuts0Acld4G5u/6H7X1iB2/8lSNDLMcmFDPWUg9GCqmnvArLbgwcYJ9la+ uVMrLQiHPZrLMOLg1XGpO8Rxazqum9tVwLMtwXREjSnMIhaJDM0Rlv9h7ySDG+Vkc682G+k2i/ZFS N8mafzgYfppxRM7h2ycA==; 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bh=N3FYJH0Na6n0IvoTQRLh82Jz6KolB+LqBxz9CxTQz94=; b=dMdEvho48GdK6q0uOpDC6L/F42yGqD6zMP7d3/DWu1YG2xKyP41yvy8Ls25V2u26R+R6mw Ll8krPj+hKwrsNoDpMuj6gqO1kVC+8FcKaFegFHR63i2FrG67i9r6U8z8dRxVmTqI13OQA NX2h+kXu06x/b60IjPtlrP5XOA2ctB2D1VbJrrCyv+UqChU71mwngXqLITHqc0KydvPqmL cbnLanbbpXYvPYaGr97h/TB2WNJjKlhWQgdfl1rKPz0RdVX3ZtPAm+UGv36GIz2XtI32oW GfA4m28YL1V5ltQLEpS1UbcvdoPPjQ7phMVD5k/7mEnV5IG5CEJjfLEZJXDryg== From: Miquel Raynal To: Rob Herring Cc: Santhosh Kumar K , broonie@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, richard@nod.at, vigneshr@ti.com, pratyush@kernel.org, mwalle@kernel.org, takahiro.kuwano@infineon.com, linux-spi@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, praneeth@ti.com, u-kumar1@ti.com, a-dutta@ti.com Subject: Re: [PATCH v3 02/13] spi: dt-bindings: cdns,qspi-nor: add PHY tuning pattern partition property In-Reply-To: (Rob Herring's message of "Wed, 3 Jun 2026 12:38:46 -0500") References: <20260527175527.2247679-1-s-k6@ti.com> <20260527175527.2247679-3-s-k6@ti.com> <20260602164945.GA475455-robh@kernel.org> <87zf1by5oc.fsf@bootlin.com> User-Agent: mu4e 1.12.7; emacs 30.2 Date: Thu, 04 Jun 2026 09:28:29 +0200 Message-ID: <87cxy6ydb6.fsf@bootlin.com> MIME-Version: 1.0 X-Last-TLS-Session-Version: TLSv1.3 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260604_002836_959601_666B2058 X-CRM114-Status: GOOD ( 24.45 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org T24gMDMvMDYvMjAyNiBhdCAxMjozODo0NiAtMDUsIFJvYiBIZXJyaW5nIDxyb2JoQGtlcm5lbC5v cmc+IHdyb3RlOgoKPiBPbiBXZWQsIEp1biAzLCAyMDI2IGF0IDExOjAx4oCvQU0gTWlxdWVsIFJh eW5hbCA8bWlxdWVsLnJheW5hbEBib290bGluLmNvbT4gd3JvdGU6Cj4+Cj4+IEhlbGxvLAo+Pgo+ PiBPbiAwMi8wNi8yMDI2IGF0IDExOjQ5OjQ1IC0wNSwgUm9iIEhlcnJpbmcgPHJvYmhAa2VybmVs Lm9yZz4gd3JvdGU6Cj4+Cj4+ID4gT24gV2VkLCBNYXkgMjcsIDIwMjYgYXQgMTE6MjU6MTZQTSAr MDUzMCwgU2FudGhvc2ggS3VtYXIgSyB3cm90ZToKPj4gPj4gUEhZIHR1bmluZyByZXF1aXJlcyBh IGtub3duIGRhdGEgcGF0dGVybiB0byBiZSByZWFkYWJsZSBmcm9tIGZsYXNoLgo+PiA+PiBXaGVu IG5vIHBhcnRpdGlvbiBpcyBleHBsaWNpdGx5IGlkZW50aWZpZWQsIHRoZSBjb250cm9sbGVyIG11 c3Qgc2VhcmNoCj4+ID4+IGFsbCBhdmFpbGFibGUgcGFydGl0aW9ucyB0byBsb2NhdGUgdGhlIHBh dHRlcm4gYnkgbGFiZWwsIHdoaWNoIGFkZHMKPj4gPj4gb3ZlcmhlYWQgYW5kIHJlbGllcyBvbiBs YWJlbCBuYW1pbmcgY29udmVudGlvbnMgb3V0c2lkZSB0aGUKPj4gPj4gY29udHJvbGxlcidzIGNv bnRyb2wuCj4+ID4KPj4gPiBJIGFncmVlICdsYWJlbCcgaXMgbm90IHRoZSBiZXN0IGNob2ljZS4g U29mdHdhcmUgc2hvdWxkIG5vdCBjYXJlIHdoYXQKPj4gPiAnbGFiZWwnIGNvbnRhaW5zLiBJdCBz aG91bGQgcmVhbGx5IGJlICdjb21wYXRpYmxlJyBpbnN0ZWFkLgo+Pgo+PiBCdXQgY29tcGF0aWJs ZSBkb2VzIG5vdCBzZWVtIHJlbGV2YW50IGluIHRoaXMgY2FzZSwgcmlnaHQ/IFdlIGFyZSBqdXN0 Cj4+IGZsYWdnaW5nIHRoZSBsb2NhdGlvbiBvZiAic29tZSB1c2VmdWwgZGF0YSBmb3IgdGhlIGNv bnRyb2xsZXIiLgo+Cj4gY29tcGF0aWJsZSBpcyB3aGF0IHRlbGxzIHVzIHdoYXQgYSByZWdpb24g Y29udGFpbnMgYW5kIGhvdyB0byB1c2UgaXQuCj4gVGhhdCBzZWVtcyBleGFjdGx5IHdoYXQgd2Ug bmVlZCB0byBkZWZpbmUgaGVyZS4KCldlIHVzdWFsbHkgdGFsayBhYm91dCAicHJvZ3JhbW1pbmcg bW9kZWwiIHdoZW4gaXQgY29tZXMgdG8gY29tcGF0aWJsZSwKaGVyZSB3ZSBqdXN0IG5lZWQgdG8g cG9pbnQgYXQgYW4gb2Zmc2V0IHdoaWNoIGlzIGluIG5vIHdheSBkaWZmZXJlbnQKKGZyb20gYSBo YXJkd2FyZSBzdGFuZHBvaW50KSB0aGFuIHRoZSBvdGhlciBvZmZzZXRzLiBJIGhvbmVzdGx5IGZl ZWwKbGlrZSBhIHBoYW5kbGUgcHJvcGVydHkgd291bGQgYmUgc2ltcGxlciwgYWxzbyBiZWNhdXNl IGNvbXBhdGlibGVzIGluCk1URCBhcmUgYWxyZWFkeSBxdWl0ZSBjb21wbGV4IHRvIG1hbmFnZSBh bmQgSSB3b3VsZCBwcmVmZXIgbm90IHRvIGFkZAptb3JlIGNvbXBsZXhpdHkgaW50byB0aGUgcGFy c2luZyBsb2dpYy4KCj4+ID4+IEFkZCBjZG5zLHBoeS1wYXR0ZXJuLXBhcnRpdGlvbiwgYSBwaGFu ZGxlIHByb3BlcnR5IHRoYXQgYWxsb3dzIHRoZSBEVAo+PiA+PiBhdXRob3IgdG8gZGlyZWN0bHkg cmVmZXJlbmNlIHRoZSBmbGFzaCBwYXJ0aXRpb24gaG9sZGluZyB0aGUgUEhZIHR1bmluZwo+PiA+ PiBwYXR0ZXJuLiBUaGUgY29udHJvbGxlciB1c2VzIHRoaXMgcGFydGl0aW9uIGR1cmluZyBjYWxp YnJhdGlvbiwgYXZvaWRpbmcKPj4gPj4gdGhlIHBhcnRpdGlvbiBzZWFyY2ggZW50aXJlbHkuCj4+ ID4KPj4gPiBEbyB5b3UgaGF2ZSBhbnkgZGF0YSB0aGF0IHRoaXMgYXBwcm9hY2ggYmVpbmcgImRp cmVjdCIgaXMgZmFzdGVyPyBJbgo+PiA+IGZhY3QsIGl0IG1pZ2h0IGJlIHdvcnNlLiBJbnN0ZWFk IG9mIHNlYXJjaGluZyBqdXN0IHRoZSBsaW1pdGVkIG51bWJlciBvZgo+PiA+IHBhcnRpdGlvbiBz dWJub2RlcywgeW91IG5vdyBzZWFyY2ggdGhlIGVudGlyZSB0cmVlIGZvciBhIG1hdGNoaW5nCj4+ ID4gcGhhbmRsZSB2YWx1ZS4gV2UgZG8gaGF2ZSBwaGFuZGxlIGNhY2hpbmcsIHNvIHRoYXQgbWln aHQgc2F2ZSB5b3UKPj4gPiBoZXJlLgo+Pgo+PiBUcnVlLCBidXQgYmVzaWRlcyBwZXJmb3JtYW5j ZSBjb25zaWRlcmF0aW9ucywgSSBwZXJzb25hbGx5IGRvIG5vdCBmaW5kCj4+IGVsZWdhbnQgdXNp bmcgYSBwYXJ0aXRpb24gbmFtZS9sYWJlbCwgYnV0IG1heWJlIHRoYXQncyBqdXN0IHBlcnNvbmFs Cj4+IHRhc3RlIDotKQo+Cj4gSSBhZ3JlZS4gVGhhdCdzIHRydWUgZm9yIGFsbCB0aGUgcGFydGl0 aW9uIG5vZGVzIHdpdGggb25seSBub2RlIG5hbWUKPiBvciBsYWJlbCB0byBnbyBvbi4gV2Ugc2hv dWxkIGZpeCB0aGF0IGF0IHRoZSBzb3VyY2UuIEhvd2V2ZXIsIHlvdQo+IGFscmVhZHkgaGF2ZSB0 byBzdXBwb3J0IHVzaW5nIGxhYmVsLAoKSHVtLCBubz8gVGhlcmUgaXMgZG93bnN0cmVhbSBzdXBw b3J0IGZvciBsYWJlbHMgaW4gVEkga2VybmVscywgYnV0IHdlCmV4cGxpY2l0bHkgYXNrZWQgU2Fu dGhvc2ggdG8gZHJvcCBpdCBmb3IgbWFpbmxpbmUgaW5jbHVzaW9uLiBIaXMgY29tbWl0Cm1lc3Nh Z2UgbWF5IGJlIGEgYml0IG1pc2xlYWRpbmcgb24gdGhpcyByZWdhcmQgYmVjYXVzZSBoZSBpcyBt ZW50aW9uaW5nCmxhYmVscyBsaWtlIGlmIHdlIHdlcmUgYWxyZWFkeSB1c2luZyB0aGVtLCBkZXNw aXRlIHRoZSBmYWN0IHRoYXQgd2UgYXJlCm5vdC4KCj4gc28gYW55dGhpbmcgZWxzZSBpcyBzdXBw b3J0aW5nIGEKPiAybmQgd2F5IHdoZXRoZXIgaXQgaXMgY29tcGF0aWJsZSBvciBhIHBoYW5kbGUg cHJvcGVydHkuIElzIGl0IHJlYWxseQo+IHdvcnRoIGl0IGhlcmU/Cj4KPiBSb2IKClRoYW5rcywK TWlxdcOobAoKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fCkxpbnV4IE1URCBkaXNjdXNzaW9uIG1haWxpbmcgbGlzdApodHRwOi8vbGlzdHMuaW5m cmFkZWFkLm9yZy9tYWlsbWFuL2xpc3RpbmZvL2xpbnV4LW10ZC8K