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 CB92ECD342C for ; Wed, 6 May 2026 08:51:27 +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:To:From:Cc:Subject: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=oMXzE2s29cy3a5t+hcZjg3pJCldm+qxkodX916KztmM=; b=lmBUTFUYwGwFziUWI3FZ5I6pZC LsDxNpbXa0fRUkqcDta6VU7GslWtcI+ldSawtZ9SjbYW9B8MKsC1O7+2IT6Dgfiz0VMBbaqgsLwqG 6MohdyRAD7faZxz8eMxm/oeIun68EqFYxlKBb/xZVTpLXy+jWkfvEufFdRosDxFCDVSZaqfGMNK+k JESWVFHP7rL4CvpAtS5NMlDTJaEJWt8Dgwf4uQHNV3XcMIRcgaG+vT9Tei2/UiB+v4CbvXl6Aj2O5 7snI+LAcndUv5niEXvaMZJx/9j8y7iIEcpKsmGKroq7pRqUusZFAPWMKfbds298CqW1BPvRmUSclz o/XRIuxA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wKXyY-00000000EN7-2uC3; Wed, 06 May 2026 08:51:26 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wKXyX-00000000ELZ-1TMI for linux-mtd@lists.infradead.org; Wed, 06 May 2026 08:51:25 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 7736A42DAB; Wed, 6 May 2026 08:51:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 059BBC2BCB8; Wed, 6 May 2026 08:51:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778057484; bh=x4Kzu3DSvB+xMkONDghyst4p2G5CH0NY5txEKz1Gx90=; h=Date:Subject:Cc:From:To:References:In-Reply-To:From; b=WcceAVYSZ12uRJJaHje+a5bxMGIQ1tnXWVnzlaPW+MWT+kPfPvlZegPXY9SCCeCCh q9BSm5PZLCJh0rH9WN6zQoYr6XVVjkOAuv6A0EWIWmvJ8QOmAhahtTc8WYXAiutfyW RxPLZrEb0mk72rUHPP0iP0x+Y2MJLivT9ZrmWuOyK6ccz183JPgdZVN1+I1sadbGZU V34XgZOt/DhmKjXmIQL45poJNT0OuD+T5icrTc+Dtr+PTxOLUcFyz3RK4lV5a64nlk Sj2YM7pq8eF+9x22vJE4HwDop8rWsMCG8lAxR27gcUDWq+LKDaxkHbfYKcytRAlhlg inmo6FFd2sF0w== Mime-Version: 1.0 Date: Wed, 06 May 2026 10:51:20 +0200 Message-Id: Subject: Re: [PATCH v4 16/27] mtd: spi-nor: Create a local SR cache Cc: "Takahiro Kuwano" , "Richard Weinberger" , "Vignesh Raghavendra" , "Jonathan Corbet" , "Sean Anderson" , "Thomas Petazzoni" , "Steam Lin" , , , From: "Michael Walle" To: "Pratyush Yadav" , "Miquel Raynal" X-Mailer: aerc 0.20.0 References: <20260403-winbond-v6-18-rc1-spi-nor-swp-v4-0-833dab5e7288@bootlin.com> <20260403-winbond-v6-18-rc1-spi-nor-swp-v4-16-833dab5e7288@bootlin.com> <2vxz7bph25qx.fsf@kernel.org> In-Reply-To: <2vxz7bph25qx.fsf@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260506_015125_406708_9699EE7F X-CRM114-Status: GOOD ( 12.79 ) 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="===============4793362709635198318==" Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org --===============4793362709635198318== Content-Type: multipart/signed; boundary=a4c0add991cee5d4c94cd50ba1c744ab3647074d71e77d29746d9541a0c5; micalg=pgp-sha384; protocol="application/pgp-signature" --a4c0add991cee5d4c94cd50ba1c744ab3647074d71e77d29746d9541a0c5 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 On Tue May 5, 2026 at 6:14 PM CEST, Pratyush Yadav wrote: > On Fri, Apr 03 2026, Miquel Raynal wrote: > >> In order to be able to generate debugfs output without having to >> actually reach the flash, create a SPI NOR local cache of the status >> registers. What matters in our case are all the bits related to sector >> locking. As such, in order to make it clear that this cache is not >> intended to be used anywhere else, we zero the irrelevant bits. >> >> The cache is initialized once during the early init, and then maintained >> every time the write protection scheme is updated. > > What is the reason for doing so? Do the reads have side effects? I don't like that a debugfs read will issue a SPI transaction, at least not these informational files. If we ever want to access the registers in the flash, we should have a separate debugfs file/interface. -michael --a4c0add991cee5d4c94cd50ba1c744ab3647074d71e77d29746d9541a0c5 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iKgEABMJADAWIQTIVZIcOo5wfU/AngkSJzzuPgIf+AUCafsBCBIcbXdhbGxlQGtl cm5lbC5vcmcACgkQEic87j4CH/iM2QGAodj/4y+LGqm9YV53c2/YGEkzVsrj3w+i ZSJBiz7L5WD3XKx7Sk0eqi30Ua6/rNXAAX4xUXCEN7Aa9xEbN6KJYu5i4NPEHL9c 5M8DqAkASm6gWJKeJXmnWRzFrjL9IVizs50= =f4lG -----END PGP SIGNATURE----- --a4c0add991cee5d4c94cd50ba1c744ab3647074d71e77d29746d9541a0c5-- --===============4793362709635198318== 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/ --===============4793362709635198318==--