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 C5566C433EF for ; Tue, 30 Nov 2021 10:03:47 +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=LMHn8prVumxFF3qqNotIJqocsP4VA43951btL1gx3ZU=; b=4L1oIUr7uAiiNO O2ugZp5Fh6u/5CP+mDODoTxEyHL0nDXcnauIXLIRX6Gq1X365XZBropTi1Ndr5qJVPhTrszWy1u5r DJHYt3T0NIVVYDGs1TDZ95WQYRIuIi+tq0aAsAjXbzo+deg6duNxxNyOWE8KB2xQ5SLCr7sk0NlW8 92P0AAlPYrvHU0G1330I+crcTtQJhfFm1aRht7eh+A0TM3Ggr2JKfi4AYa4j6NoWV7ZUtUhZys+pt pPN8b/xmnbAfxmZu/BH/giQv21yd23jr4dssWKTbEY2oQ8KPM9Iaxiz6x4qz0V/348aU24tqJvESp FtLmCWwDQrKF5Hzl3ZzA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mrzyh-004U4R-Br; Tue, 30 Nov 2021 10:03:11 +0000 Received: from fllv0016.ext.ti.com ([198.47.19.142]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mrzm0-004Pi0-Fl for linux-mtd@lists.infradead.org; Tue, 30 Nov 2021 09:50:06 +0000 Received: from lelv0265.itg.ti.com ([10.180.67.224]) by fllv0016.ext.ti.com (8.15.2/8.15.2) with ESMTP id 1AU9o01L083094; Tue, 30 Nov 2021 03:50:00 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1638265800; bh=7xhhlicdSvFPl57W3W68n3eLENoVyST+z3lW9HfMOQM=; h=Date:From:To:CC:Subject:References:In-Reply-To; b=KDgRXyqfU5+r5knpQEzz5dbKAphannLIuJQo+fgKFIst+mcF+gZ7txBYnJqzzkjpF jETpBSlYeQu5TPwWrVLssbuzP5qG/mqvKfdToUd4Dlt/Z7kqJmAz+j/J60IHdUZr25 hdMsQv867bhrebxQuRBNUFyQc3YCCDSvssMrKAqs= Received: from DLEE114.ent.ti.com (dlee114.ent.ti.com [157.170.170.25]) by lelv0265.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 1AU9o0dx104790 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 30 Nov 2021 03:50:00 -0600 Received: from DLEE101.ent.ti.com (157.170.170.31) by DLEE114.ent.ti.com (157.170.170.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.14; Tue, 30 Nov 2021 03:50:00 -0600 Received: from lelv0327.itg.ti.com (10.180.67.183) by DLEE101.ent.ti.com (157.170.170.31) 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; Tue, 30 Nov 2021 03:50:00 -0600 Received: from localhost (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0327.itg.ti.com (8.15.2/8.15.2) with ESMTP id 1AU9nxVX077201; Tue, 30 Nov 2021 03:49:59 -0600 Date: Tue, 30 Nov 2021 15:19:58 +0530 From: Pratyush Yadav To: Alexander Sverdlin CC: Michael Walle , , Tudor Ambarus , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Subject: Re: [PATCH] mtd: spi-nor: mt25qu: Ignore 6th ID byte Message-ID: <20211130094956.h7mpaucciam2taco@ti.com> References: <20211119080402.20262-1-alexander.sverdlin@nokia.com> <9a158e2ef6635212c1e353590e3b773b@walle.cc> <1e133bc6-5edb-c4ce-ad44-3de77048acf2@nokia.com> <85251c3b-13c1-8b24-0ce2-6793ea55e39a@nokia.com> <20211123174206.bzh5yq2f7sgkqpmi@ti.com> <8742b6e8-c26e-47d7-0b77-67137d3de10f@nokia.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <8742b6e8-c26e-47d7-0b77-67137d3de10f@nokia.com> User-Agent: NeoMutt/20171215 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-20211130_015004_655258_C7281BC6 X-CRM114-Status: GOOD ( 21.40 ) 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="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org On 25/11/21 08:26AM, Alexander Sverdlin wrote: > Hi Pratyush, > > thanks for the quick reply! > > On 23/11/2021 18:42, Pratyush Yadav wrote: > >> In my opinion, as I look into Micron or Macronix datasheets, write_proto has little to > >> do with erase_proto. (there is currently no separate erase_proto) > > I think this just worked for most flashes since both writes and erases > > generally use 1-bit mode. 4 or 8 bit modes are generally used for reads > > only. > > > >> Before I come up with a totally wrong patch, wanted to ask your opinion, how should > >> it be solved, what do you think? > >> > >> I do not see any erase-related tables for this in JESD216C. > >> I also cannot come up with an example of a chip with erase != 1-1-0. > > See Micron MT35XU512ABA or Cypress S28HS512T (in spansion.c). Both have > > erase in 8D-8D-8D mode. > > > >> Shall I hardcode 1-1-0 for erase? > >> Shall I introduce erase_proto? What would be the logic for its setting/discovery? > > I think introducing erase_proto would be the sensible thing. You would > > have to see if we can discover erase protocol from SFDP. But my question > > is: is that really worth it? Do you really need that little bit speed > > boost you'd get by transmitting write data in 4 bit mode, since the > > large portion of the time would be spent in the chip actually flashing > > the data. > > The problem I have is not speed, but totally not working erase. And I don't want > to downgrade write functionality for other chips. Then you need to introduce erase_proto. -- Regards, Pratyush Yadav Texas Instruments Inc. ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/