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 882D0C433EF for ; Wed, 18 May 2022 08:10:18 +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-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:CC:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=AlZSvOxubVYllSBiXvRrEOOjAVjbHEzmUIw2XwadnJ0=; b=acL4SRHfgwnNTd D8VToTxh2ao2Kjbu+lj7uKx5q6DGig8fGc19FPeQ+TFX97KLgh58rxTgaocubm5UdTXHMF7zum4XU aOKld6TMQNqvfBrg+e3CZoArZuCLZCi7hcIDBSrSYyfW4QTvbzBCuWwa5gR7Vt0SzyGqzLh+okHcZ JckqhFyBksQepLDeuPitI+SBX0w58DoX+PgrqMOhG3+JCbmEMFRTCcVSh+q63+jFNlg4eV0ibBK17 csfm+GxdT0VmVsaHIfyAYius+NmbR/z/RDMIWizmeNpKgtXg52uh8pptLKqMK2R7AZy6GLjoSjLNC haGyxHGSKepxmvVuYAMA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nrEjm-000PE1-Fl; Wed, 18 May 2022 08:08:54 +0000 Received: from lelv0143.ext.ti.com ([198.47.23.248]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nrEYQ-000Iud-P7; Wed, 18 May 2022 07:57:12 +0000 Received: from lelv0266.itg.ti.com ([10.180.67.225]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id 24I7urPV024570; Wed, 18 May 2022 02:56:53 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1652860613; bh=P4F7f/HFsSYJM14QiiyJ/DYiatoS1hZl6AKwPrhOcoc=; h=Date:From:To:CC:Subject:References:In-Reply-To; b=Q7f2wKZ5U0/Xc6zelmerAA6VpUUqLbj76051mZjFB2TT3LcpYikXiGvDEdUZ7BRRD lbEGeaWr0KOTwQ3nsrHlGWziA7EgBLTIx1V07RZUjqKuGXK0Iwun2ehqI496imAjrB gUIJQVdfBH/QtjxcK2EWSBek7kN3UQBu9StDXTI8= Received: from DLEE102.ent.ti.com (dlee102.ent.ti.com [157.170.170.32]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 24I7urAZ109191 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 18 May 2022 02:56:53 -0500 Received: from DLEE102.ent.ti.com (157.170.170.32) by DLEE102.ent.ti.com (157.170.170.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.14; Wed, 18 May 2022 02:56:52 -0500 Received: from fllv0039.itg.ti.com (10.64.41.19) by DLEE102.ent.ti.com (157.170.170.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.14 via Frontend Transport; Wed, 18 May 2022 02:56:52 -0500 Received: from localhost (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0039.itg.ti.com (8.15.2/8.15.2) with ESMTP id 24I7uq2S005572; Wed, 18 May 2022 02:56:52 -0500 Date: Wed, 18 May 2022 13:26:51 +0530 From: Pratyush Yadav To: Miquel Raynal CC: Nishanth Menon , Tero Kristo , Rob Herring , Tudor Ambarus , Michael Walle , Richard Weinberger , Vignesh Raghavendra , Mark Brown , =?utf-8?Q?C=C3=A9dric?= Le Goater , , , , , Subject: Re: [RFC PATCH 3/6] mtd: spi-nor: core: run calibration when initialization is done Message-ID: <20220518075651.mvdhfnfbgutecgyq@ti.com> References: <20210311191216.7363-1-p.yadav@ti.com> <20210311191216.7363-4-p.yadav@ti.com> <20220517160226.4107f282@xps-13> <20220518060640.os5fp5rez4ie7qc4@ti.com> <20220518091931.279c5398@xps-13> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220518091931.279c5398@xps-13> X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220518_005710_993349_7552478C X-CRM114-Status: GOOD ( 44.74 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 18/05/22 09:19AM, Miquel Raynal wrote: > Hi Pratyush, > = > p.yadav@ti.com wrote on Wed, 18 May 2022 11:37:05 +0530: > = > > +Cedric > > = > > On 17/05/22 04:02PM, Miquel Raynal wrote: > > > Hi Pratyush, > > > = > > > p.yadav@ti.com wrote on Fri, 12 Mar 2021 00:42:13 +0530: > > > = > > > > Once the flash is initialized tell the controller it can run > > > > calibration procedures if needed. This can be useful when calibrati= on is > > > > needed to run at higher clock speeds. > > > > = > > > > Signed-off-by: Pratyush Yadav > > > > --- > > > > drivers/mtd/spi-nor/core.c | 12 ++++++++++-- > > > > 1 file changed, 10 insertions(+), 2 deletions(-) > > > > = > > > > diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c > > > > index 88888df009f0..e0cbcaf1be89 100644 > > > > --- a/drivers/mtd/spi-nor/core.c > > > > +++ b/drivers/mtd/spi-nor/core.c > > > > @@ -3650,6 +3650,7 @@ static int spi_nor_probe(struct spi_mem *spim= em) > > > > * checking what's really supported using spi_mem_supports_op(). > > > > */ > > > > const struct spi_nor_hwcaps hwcaps =3D { .mask =3D SNOR_HWCAPS_AL= L }; > > > > + struct spi_mem_op op; > > > > char *flash_name; > > > > int ret; > > > > = > > > > @@ -3709,8 +3710,15 @@ static int spi_nor_probe(struct spi_mem *spi= mem) > > > > if (ret) > > > > return ret; > > > > = > > > > - return mtd_device_register(&nor->mtd, data ? data->parts : NULL, > > > > - data ? data->nr_parts : 0); > > > > + ret =3D mtd_device_register(&nor->mtd, data ? data->parts : NULL, > > > > + data ? data->nr_parts : 0); > > > > + if (ret) > > > > + return ret; > > > > + > > > > + op =3D spi_nor_spimem_get_read_op(nor); = > > > = > > > Isn't this too specific? I really don't know much about spi-nors, but= I > > > find odd to have this op being created here, why not moving this into > > > the _do_calibration() helper? = > > = > > Maybe the naming confused you but this is a function in the SPI NOR = > > core, not in SPI MEM. SPI NOR supports both SPI MEM based controllers = > > and "legacy" controllers, so the convention is to add the "spimem" = > > prefix before SPI MEM specific functions. So I don't get the comment = > > about it being too specific. It is too specific to what? > = > Mmh right, it's fine then. > = > > = > > And how can spi_mem_do_calibration() know what op the flash uses to rea= d = > > data? SPI NOR or SPI NAND would know it, but not SPI MEM. That is why w= e = > > pass in that information to spi_mem_do_calibration(). > = > But here the op is "spi-nor wide", I would have expected a > per-device op. But that is not a big deal, that is something that can > also be updated later if needed I guess. It is per-device. The op is generated using nor->read_opcode, = nor->addr_width, nor->read_dummy, etc. So if you have 2 NOR flashes on = your system with different opcodes, it would work for both. > = > One last question, is there something that mtd_device_register() does > that is really needed for the calibration to work? Otherwise I would > rather prefer to have that calibration happening before the user gets > access to the device. The calibration works by reading a known pattern that is already written = to the flash again and again and seeing what delays work and what don't. = For that to happen, the controller driver needs to know where the = pattern is stored. This series does that by looking at the MTD = partitions. For that to happen, we need to create those partitions = first, which happens after mtd_device_register(). But I am planning to use device tree to get that information now so this = should no longer be needed and we can do calibration before registering = the device with MTD. > = > > = > > > = > > > > + spi_mem_do_calibration(nor->spimem, &op); = > > > = > > > A warning/info upon calibration error (not on the absence of the hook) > > > would be nice? = > > = > > Yes, agreed. > > = > > > = > > > > + > > > > + return 0; > > > > } > > > > = > > > > static int spi_nor_remove(struct spi_mem *spimem) = > > > = > > > Otherwise I like the overall idea. = > > = > > Thanks for reviewing. > > = > > > = > > > Thanks, > > > Miqu=E8l = > > = > = > = > Thanks, > Miqu=E8l -- = Regards, Pratyush Yadav Texas Instruments Inc. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel