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 970D0CD5BD5 for ; Thu, 28 May 2026 07:52:18 +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-Type: List-Subscribe:List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: In-Reply-To:References:From:Cc:Subject:To:Message-Id:Date:Mime-Version: Reply-To:Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date :Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=G13d+CZPpFr4gqbNEzx6Wh4TSoLw1kvAAM+aQxDiMTo=; b=lWYgahoJa0gW3G72wdihm+7lxS LsyIIvUW6UmDW7z89GtY1/Gp+nFuXINtRTFG/kOWvSdOec7IHV9lC9/JYm+HJDHWfpwvorW6Dtoo2 xsETqGacL+DEyzA3ABbwhg/bm9Ow1XzJU9becC3clSIKYZmavnOSSMYwLo8pzSf3MlAdpp/wsFaaj mzTwunbQXac0RNiquFQYxYQXY1QaGJemzRbxNL/cGz/e+jjhgZOPVFxd1AjEJnzPkNSSkB6KJJ7LF 2kMdQTz/5KmwCSbdp9JL3qc6uBeTpSCi2w48ZIqrFfLlwzOnh2E/DbEB0lngZ0/HNJI3aOgRREVyv sg5WBACQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wSVXM-00000005JDz-1SHw; Thu, 28 May 2026 07:52:16 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wSVXJ-00000005JDb-06xy for linux-mtd@lists.infradead.org; Thu, 28 May 2026 07:52:14 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with UTF8SMTP id 8316040589; Thu, 28 May 2026 07:52:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with UTF8SMTPSA id E265F1F00A3A; Thu, 28 May 2026 07:52:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779954732; bh=2GMkjPxX2bdw46i4uwyD0Ly6pBU0GmTzAqTMf4hdkRI=; h=Date:To:Subject:Cc:From:References:In-Reply-To; b=kmGPG3q+QT6ER7LA5P38moW3cF68TRwJfA/25p9dCUS681urOmZikYpa3cXzLHpXI 6P6zA9g78QE2BIS+xXG365jtFUENZSM0aWpXrkjohntXrSgDNbP3VeWuUVmbS9Ebwa zrX9CcXyONX6+H8tU1lUfaE7pqYwpFo/Dxdsli1VBYEI6My0gaJI9SO0C36EUDNOBh apVBl5uNNpqWkMSWk8SgAcstMXo7FdYq57bt9uP7T/HC7HZXvGrpz0LKp96otJ1vcS ITF+Bwc8U7MfBg6sL/0OTAyN1u6sCbq4SxtzRIqycbEZN8XrzwZuDGkQMN0Xjszd5D tUHrEgo7HFG5A== Mime-Version: 1.0 Date: Thu, 28 May 2026 09:52:08 +0200 Message-Id: To: "Miquel Raynal" , "Cheng Ming Lin" Subject: Re: [PATCH] mtd: spi-nor: Add support for MX25L12833F and MX25L12845G Cc: "Pratyush Yadav" , "Takahiro Kuwano" , "Richard Weinberger" , "Vignesh Raghavendra" , , , , "Cheng Ming Lin" From: "Michael Walle" X-Mailer: aerc 0.20.0 References: <20260528051751.1648246-1-linchengming884@gmail.com> <87eciwhtf8.fsf@bootlin.com> In-Reply-To: <87eciwhtf8.fsf@bootlin.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260528_005213_117597_28529051 X-CRM114-Status: GOOD ( 18.07 ) 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: multipart/mixed; boundary="===============6915161059078174304==" Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org --===============6915161059078174304== Content-Type: multipart/signed; boundary=925f76c6de4a818e9399224f463366c077bdf0fc82b27f5e98e940a62e31; micalg=pgp-sha384; protocol="application/pgp-signature" --925f76c6de4a818e9399224f463366c077bdf0fc82b27f5e98e940a62e31 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Hi, On Thu May 28, 2026 at 9:42 AM CEST, Miquel Raynal wrote: > Hi Cheng Ming, > >>> It looks like you're getting bitten by the ID reuse. You can't just >>> unconditionally add the quad PP because as far as I can see the >>> MX25L12805D [1] is just a standard single bit i/o flash and doesn't >>> support the 4PP. >> >> You are absolutely right. Thanks for catching this. >> >> The MX25L12805D is indeed a much older product (released around 2009). >> Since the initial JESD216 SFDP standard wasn't published until 2011, >> I double-checked with our internal PM and confirmed that the MX25L12805D >> does not support SFDP at all. >> >> Since the newer flashes (MX25L12833F and MX25L12845G) do support SFDP, >> we could use this as a differentiator to distinguish them from the legac= y >> MX25L12805D. >> >> What if we try to read the SFDP signature (RDSFDP) in the fixup hook? >> If a valid SFDP signature is detected, we can safely identify it as the >> newer flash and apply the SNOR_HWCAPS_PP_1_4_4 capability. If there is >> no SFDP signature, we leave it as is for the legacy MX25L12805D. >> >> Do you think this approach is feasible and acceptable? If so, I will >> implement this logic and submit a v2 patch. > > The ->post_sfdp() fixup hook is documented as "not called for SPI NORs > that do not support SFDP". Alternatively, I believe an earlier hook, > like ->post_bfpt() could also work since it does not seem to run on > non SFDP compatible flashes. Moreover: * spi_nor_post_sfdp_fixups() is called after the SFDP tables are parsed= . * It is used to tweak various flash parameters when information provide= d * by the SFDP tables are wrong. And it looks like that is the case for these flashes. Also, please provide a comment on the fixup describing that the flash misses that property. Basically, what you've written in the commit message. -michael --925f76c6de4a818e9399224f463366c077bdf0fc82b27f5e98e940a62e31 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iKgEABMJADAWIQTIVZIcOo5wfU/AngkSJzzuPgIf+AUCahf0KBIcbXdhbGxlQGtl cm5lbC5vcmcACgkQEic87j4CH/hD6gF9EgLZdXSAupg/3ipw2fvtR9bRXS5g/Pvx X8fTvB0ix0lcfAVEkuVUAjtOJTxr/9yuAX9aFnjlczgHvO2Wg4aaRy7Af6up486X /WhadFLeFZAUdcjw6Uy4iGdYLtn/aYT5lhw= =/t2e -----END PGP SIGNATURE----- --925f76c6de4a818e9399224f463366c077bdf0fc82b27f5e98e940a62e31-- --===============6915161059078174304== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ --===============6915161059078174304==--