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 D1283CD6E4A for ; Tue, 2 Jun 2026 12:36:30 +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=WXOqS+eUrcf6rFdbWEU0O0XSU9+03yXl5tMTTywTqcU=; b=jAMTx8+avTj+ww 839iCKkDiB8SmPrQiSJ0ABE0wILVB1GlMYe13vycRBmVPCz9Z611gJ/ZsHC6LwgGX7p4bGiKM8V5a eKCfEVGXw2WkSCZdqFSxLKasAo2BZnEatg8nVpcBh/H0Pt1Ohj/6mLP684D0fhQuZudoO5Mwfvs7f hMpyimOBPrbfDe/il+imRpcty2Kd/3evZ7HaI2RavAg851GlXnWc29xbUED/zFAKe/Rj0OGsQGKxG EWRDGr3qt55+n2K1AA0nuuspmlx5lzRaaILjuNXfGh7UySs6qhbDp7NeVmWdl8nXlm4soOjrlNVp9 OurxKUvHMdu6XbQkiweQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wUOM9-0000000Czve-1Oz6; Tue, 02 Jun 2026 12:36:29 +0000 Received: from smtpout-03.galae.net ([185.246.85.4]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wUOM5-0000000Czv2-3iwH for linux-mtd@lists.infradead.org; Tue, 02 Jun 2026 12:36:27 +0000 Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-03.galae.net (Postfix) with ESMTPS id 71FE54E42DC0; Tue, 2 Jun 2026 12:36:23 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 43069603BC; Tue, 2 Jun 2026 12:36:23 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 5CE99108883E7; Tue, 2 Jun 2026 14:36:18 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1780403782; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=SRPRaAh+bKL/wfIfWcgbiLpj4JaAtntWVoPHMgKJ5hk=; b=IzdBcF7KMuSb7rZ5XB+aZYiM0E5ckcEKMIFaaFmESlAG2XXd/oPBYuAePWkIA+1XVt8AnE Uaae1GYa00ns3rwjBIIHI8NNiSRjpJ/HlnFxpC3VQjR21RTIaezCw4oUPpdI0Vb4S8sBE+ 9YG3xXTIGSm/2KP05PNUZNU5X1zOOayandiof2fO57ZKW4Cna75LUsxYSzHOF4SSldoRgs XZMzpGuHNAMXLxwgIKqtuZPCl1GVYEweyOfHNkDN699VQawnNiUZabi3YJ79OVIGpwCqRZ PDPoMjuKitoxIWOn2lQn18DJxCtPkpODwqQcIjYPub9VBM+0aypiC4umizGmHQ== From: Miquel Raynal To: Santhosh Kumar K Cc: Krzysztof Kozlowski , , , , , , , , , , , , , , , , Subject: Re: [PATCH v3 02/13] spi: dt-bindings: cdns,qspi-nor: add PHY tuning pattern partition property In-Reply-To: <4a570d36-dda6-4f3d-9c16-d3e57ac55f1c@ti.com> (Santhosh Kumar K.'s message of "Tue, 2 Jun 2026 12:00:36 +0530") References: <20260527175527.2247679-1-s-k6@ti.com> <20260527175527.2247679-3-s-k6@ti.com> <20260530-original-peccary-of-cubism-af68ed@quoll> <2f091813-fa28-407f-892d-bbbbe3cac4e4@ti.com> <063fe976-9a28-4670-90df-921fbc1c3a8c@kernel.org> <20260601-stirring-tested-mayfly-e97c14@quoll> <4a570d36-dda6-4f3d-9c16-d3e57ac55f1c@ti.com> User-Agent: mu4e 1.12.7; emacs 30.2 Date: Tue, 02 Jun 2026 14:36:17 +0200 Message-ID: <87mrxd15mm.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-20260602_053626_056800_30705708 X-CRM114-Status: UNSURE ( 8.81 ) X-CRM114-Notice: Please train this message. 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 SGVsbG8sCgo+Pj4+PiBJIGFsc28gaGF2ZSBkb3VidHMgdGhhdCB0aGlzIGlzIHBlci1kZXZpY2Ug cHJvcGVydHkuIFlvdXIgY29tbWl0IG1zZwo+Pj4+PiBzdWdnZXN0cyBpdCBpcyBwZXIgY29udHJv bGxlci4KPj4+Pgo+Pj4+IFRoaXMgaXMgYSBwZXItZGV2aWNlIHByb3BlcnR5LiBJdCBpcyBjb25z dW1lZCBieSB0aGUgY29udHJvbGxlciBkcml2ZXIKPj4+PiBvbmx5IHRvIGxvY2F0ZSBhbmQgcmV0 cmlldmUgdGhlIG9mZnNldCBvZiB0aGUgUEhZIHBhdHRlcm4gcGFydGl0aW9uCj4+Pgo+Pj4gU28g d2l0aCB0d28gZGV2aWNlcyBvbiBhIGJ1cywgeW91IG5lZWQgdHdvIHNlcGFyYXRlIHBhcnRpdGlv bnMgZm9yIHR1bmluZz8KPgo+IEVhY2ggU1BJIE5PUiBmbGFzaCBkZXZpY2UgbmVlZHMgYSBwYXJ0 aXRpb24gdG8gc3RvcmUgUEhZIHR1bmluZwo+IHBhdHRlcm4uCgpJZiBJIG1heSB0cnkgdG8gZXhw bGFpbiBhIGJpdCB3aGF0IGlzIGJlaGluZCwgdGhlIHJlYWQgdHVuaW5nIHByb2NlZHVyZQppcyBh Ym91dCByZWFkaW5nIGRhdGEgZnJvbSB0aGUgc3BpIG1lbW9yeSBjYWNoZSAoc29tZSBraW5kIG9m IGludGVybmFsClNSQU0pIG92ZXIgYW5kIG92ZXIgYWdhaW4sIHdoaWxlIHR1bmluZyB0aGUgY29u dHJvbGxlciBwYXJhbWV0ZXJzIHVudGlsCndlIGdldCB0aGUgYmVzdCBzdGFiaWxpdHkgKHRoZSBj b250cm9sbGVyIGRyaXZlciBrbm93cyB0aGUgcGF0dGVybiBpdAptdXN0IGdldCkuIFdoaWxlIFNQ SSBOQU5EIGNoaXBzIGhhdmUgIndyaXRlIHRvIGNhY2hlIiBvcGNvZGVzIHRoYXQgY291bGQKYmUg dXNlZCB0byBsb2FkIHRoZSBwYXR0ZXJuIGludG8gdGhlIGNoaXAgd2l0aG91dCBhbnkgYWN0dWFs IHJlYWQgZnJvbQp0aGUgbWVtb3J5IGFycmF5LCB0aGlzIGlzIG5vdCBwb3NzaWJsZSB3aXRoIFNQ SSBOT1IgZGV2aWNlcyB3aGljaCBkbyBub3QKaGF2ZSBzdWNoIGNhcGFiaWxpdHkuIFNpbmNlIHdl IHdhbnQgdG8ga2VlcCB0aGlzIHRyYWluaW5nIHByb2NlZHVyZQptZW1vcnkgYWdub3N0aWMgKGFu ZCBhbHNvIHNvbWV3aGF0IHNpbXBsZSksIHdlIHNoYWxsIGV4cGVjdCBvbmUgcGF0dGVybgpwZXIg bWVtb3J5LgoKVGhhbmtzLApNaXF1w6hsCgpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX18KTGludXggTVREIGRpc2N1c3Npb24gbWFpbGluZyBsaXN0 Cmh0dHA6Ly9saXN0cy5pbmZyYWRlYWQub3JnL21haWxtYW4vbGlzdGluZm8vbGludXgtbXRkLwo= 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 EBD14394EA6; Tue, 2 Jun 2026 12:36:24 +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=1780403787; cv=none; b=TZuH2FPUW28GArV77kshQVvGcgejqxzP+8qlx/2YTQ/cc/mvCJBRYnh0F783hy3bOFyTcWq5LiQjwYg+vBv534jaCN20R/3MHajdY/hFG+SGdjs+vLJRxrdvib27fsA4AEh1dhQPomtaONOn43Ib938mMBQVQXrq0cU628gkzH4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780403787; c=relaxed/simple; bh=SRPRaAh+bKL/wfIfWcgbiLpj4JaAtntWVoPHMgKJ5hk=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=aFzCUsUUTyCQWphJ2iZacqVF/PnJTyC9Cp2XIgCJkWWu/qTomCFrIThlJK+Dhb2oOwIrsaPb2CdHYAoXpQUMr1c++1aQiQYnNb9ExCwUHpV2VsVeEmUX8yWlp/o3ThuLa8d8+AQpbcvI+APDqBsyWJj17C8wIaICv19qY/xbUbs= 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=IzdBcF7K; 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="IzdBcF7K" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-03.galae.net (Postfix) with ESMTPS id 71FE54E42DC0; Tue, 2 Jun 2026 12:36:23 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 43069603BC; Tue, 2 Jun 2026 12:36:23 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 5CE99108883E7; Tue, 2 Jun 2026 14:36:18 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1780403782; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=SRPRaAh+bKL/wfIfWcgbiLpj4JaAtntWVoPHMgKJ5hk=; b=IzdBcF7KMuSb7rZ5XB+aZYiM0E5ckcEKMIFaaFmESlAG2XXd/oPBYuAePWkIA+1XVt8AnE Uaae1GYa00ns3rwjBIIHI8NNiSRjpJ/HlnFxpC3VQjR21RTIaezCw4oUPpdI0Vb4S8sBE+ 9YG3xXTIGSm/2KP05PNUZNU5X1zOOayandiof2fO57ZKW4Cna75LUsxYSzHOF4SSldoRgs XZMzpGuHNAMXLxwgIKqtuZPCl1GVYEweyOfHNkDN699VQawnNiUZabi3YJ79OVIGpwCqRZ PDPoMjuKitoxIWOn2lQn18DJxCtPkpODwqQcIjYPub9VBM+0aypiC4umizGmHQ== From: Miquel Raynal To: Santhosh Kumar K Cc: Krzysztof Kozlowski , , , , , , , , , , , , , , , , Subject: Re: [PATCH v3 02/13] spi: dt-bindings: cdns,qspi-nor: add PHY tuning pattern partition property In-Reply-To: <4a570d36-dda6-4f3d-9c16-d3e57ac55f1c@ti.com> (Santhosh Kumar K.'s message of "Tue, 2 Jun 2026 12:00:36 +0530") References: <20260527175527.2247679-1-s-k6@ti.com> <20260527175527.2247679-3-s-k6@ti.com> <20260530-original-peccary-of-cubism-af68ed@quoll> <2f091813-fa28-407f-892d-bbbbe3cac4e4@ti.com> <063fe976-9a28-4670-90df-921fbc1c3a8c@kernel.org> <20260601-stirring-tested-mayfly-e97c14@quoll> <4a570d36-dda6-4f3d-9c16-d3e57ac55f1c@ti.com> User-Agent: mu4e 1.12.7; emacs 30.2 Date: Tue, 02 Jun 2026 14:36:17 +0200 Message-ID: <87mrxd15mm.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 Hello, >>>>> I also have doubts that this is per-device property. Your commit msg >>>>> suggests it is per controller. >>>> >>>> This is a per-device property. It is consumed by the controller driver >>>> only to locate and retrieve the offset of the PHY pattern partition >>> >>> So with two devices on a bus, you need two separate partitions for tuni= ng? > > Each SPI NOR flash device needs a partition to store PHY tuning > pattern. If I may try to explain a bit what is behind, the read tuning procedure is about reading data from the spi memory cache (some kind of internal SRAM) over and over again, while tuning the controller parameters until we get the best stability (the controller driver knows the pattern it must get). While SPI NAND chips have "write to cache" opcodes that could be used to load the pattern into the chip without any actual read from the memory array, this is not possible with SPI NOR devices which do not have such capability. Since we want to keep this training procedure memory agnostic (and also somewhat simple), we shall expect one pattern per memory. Thanks, Miqu=C3=A8l