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 590BDC0015E for ; Wed, 19 Jul 2023 09:26:29 +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:In-Reply-To: Date:References: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=FOWPoABlj+PTQH0F/KjYW9a9YsH9NEuxP6JYHl/DiA8=; b=Dw4lyWjLqXvTR8 NFOkTW5vlmTQJLpzh5q96lhUKVU4gaM5XfR5j/STfprpjbi3GG4cCITjC/Cds0g/4h4rqsvAEH0PE iQJqWnGTxxzG0YqgPB/zCbEutWaPFHXoezdRVz2htNbv6Taf29VQ/C39KDFr3560zYwxzxKgQlufp YHiY+vQxdK92Kt3YYBXCJ3HVSa11z4eSI3GODNzdbrlGIBslGouIhN0FJfq28rCNLcxXBF7YFZqwZ lRKQ3XNnTAB6S+QVFuCzspiD0avMFfpOX/c6qIX3ekr6E4U3TQ8l/deiYMMSFTob537LmwcocdE6b 0a2Y7cQbV7l/T+7svm+w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qM3Rr-006XYM-25; Wed, 19 Jul 2023 09:26:19 +0000 Received: from unicorn.mansr.com ([81.2.72.234]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qM3Ro-006XW0-28 for linux-mtd@lists.infradead.org; Wed, 19 Jul 2023 09:26:18 +0000 Received: from raven.mansr.com (raven.mansr.com [IPv6:2001:8b0:ca0d:1::3]) by unicorn.mansr.com (Postfix) with ESMTPS id 819F615360; Wed, 19 Jul 2023 10:26:09 +0100 (BST) Received: by raven.mansr.com (Postfix, from userid 51770) id 735E4219B40; Wed, 19 Jul 2023 10:26:09 +0100 (BST) From: =?iso-8859-1?Q?M=E5ns_Rullg=E5rd?= To: Miquel Raynal Cc: Richard Weinberger , Vignesh Raghavendra , Tudor Ambarus , Pratyush Yadav , Michael Walle , , Julien Su , Jaime Liao , Alvin Zhou , Thomas Petazzoni , JaimeLiao , Alexander Shiyan , Domenico Punzo , Bean Huo Subject: Re: [PATCH v2 3/3] mtd: rawnand: Support for sequential cache reads References: <20230112093637.987838-1-miquel.raynal@bootlin.com> <20230112093637.987838-4-miquel.raynal@bootlin.com> <20230716174917.3a9ca7a7@xps-13> <20230717091900.52ed815a@xps-13> <20230717183645.32ef90b0@xps-13> <20230719102153.2ef93cfe@xps-13> Date: Wed, 19 Jul 2023 10:26:09 +0100 In-Reply-To: <20230719102153.2ef93cfe@xps-13> (Miquel Raynal's message of "Wed, 19 Jul 2023 10:21:53 +0200") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230719_022616_849617_D7E038A9 X-CRM114-Status: GOOD ( 26.66 ) 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="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org Miquel Raynal writes: > Hi M=E5ns, > > mans@mansr.com wrote on Tue, 18 Jul 2023 15:03:14 +0100: > >> Miquel Raynal writes: >> = >> > Hi M=E5ns, >> > >> > mans@mansr.com wrote on Mon, 17 Jul 2023 14:11:31 +0100: >> > = >> >> Miquel Raynal writes: >> >> = >> >> > So, I should have done that earlier but, could you please slow the >> >> > whole operation down, just to see if there is something wrong with = the >> >> > timings or if we should look in another direction. >> >> > >> >> > Maybe you could add a boolean to flag if the last CMD was a >> >> > READCACHESEQ, READCACHESTART or READCACHEEND, and if the flag is >> >> > true, please get the jiffies before and after each waitrdy and >> >> > delay_ns. Finally, please print the expected delay and the actual o= ne >> >> > and compare to see if something was too fast compared to what we >> >> > expected. = >> >> = >> >> Between which points exactly should the delay be measured? Also, the= re >> >> is no command called READCACHESTART. Did you mean READSTART or >> >> something else? = >> > >> > Yeah, whatever command is specific to sequential cache reads: >> > https://elixir.bootlin.com/linux/latest/source/drivers/mtd/nand/raw/na= nd_base.c#L1218 >> > https://elixir.bootlin.com/linux/latest/source/drivers/mtd/nand/raw/na= nd_base.c#L1228 = >> = >> I'm still not sure what exactly you want to me measure. The waitrdy and >> ndelay combined, each separately, or something else? >> = > > I would like to know, how much time we spend waiting in both cases. Which "both" cases? > Is there something wrong with the "wait ready"? As we cannot observe > the timings with a scope, because we are using a "soft" controller > implementation somehow, we can easily measure how much time we spend > in each operation by measuring the time before and after. > > These information are only useful when we are doing operations related > to sequential reads. I have hooked up some spare GPIOs to a scope, which should be more accurate (nanosecond) than software timestamps. All I need to know is what to measure and what to look for in those measurements. -- = M=E5ns Rullg=E5rd ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/