From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Thu, 19 Dec 2024 11:28:40 +0100 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1tODln-00A06A-3A for lore@lore.pengutronix.de; Thu, 19 Dec 2024 11:28:40 +0100 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1tODln-000107-RJ for lore@pengutronix.de; Thu, 19 Dec 2024 11:28:40 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Ib2p7Nbbsj7xOceOPdYwLgcR+CRmF1QUwaRJ7fTZ5wI=; b=iw1JXp5a1aZa6xgUrXiwm0/0q5 qSZ/t7lxVU3ou0mcg+91Ax5CZjl9XNxxzyByx70WVkNye6lGulLf3696ajkY57T/g0Li9jArMPrNS b1vAg/tx6hQytyuLEy57LG5LE5ya7zKJJvV+K64OifU91MwbQrOOHP2c9taLJwdnXcJ+zMRRrsXDM RihPaBnvIk9+w/SuTdnCpJqzSNoqXuhIMnie8q1TeUb+3HzBCM9ZpxNUooAmGbc4z1VwDH6sgSjZ+ W2miuprF3nB9kMR45KmJH1SZtfyWVw2hZt1GwDZ2b/3narxWUFEWdEkStYReRy5Lr2Mx4w3JDWec5 LV6B7bdQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tODlA-00000001XxW-1S99; Thu, 19 Dec 2024 10:28:00 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tODl6-00000001Xwm-30ir for barebox@lists.infradead.org; Thu, 19 Dec 2024 10:27:58 +0000 Received: from ptz.office.stw.pengutronix.de ([2a0a:edc0:0:900:1d::77] helo=[127.0.0.1]) by metis.whiteo.stw.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1tODl3-0000n4-4d; Thu, 19 Dec 2024 11:27:53 +0100 Message-ID: <2200ece8-593b-4ac3-be3e-b05570165e5e@pengutronix.de> Date: Thu, 19 Dec 2024 11:27:52 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird To: Peng Fan , "Peng Fan (OSS)" Cc: U-Boot Mailing List , "barebox@lists.infradead.org" , dl-uboot-imx , Steffen Trumtrar References: <8074530f-720b-4aea-934b-c0643c356617@pengutronix.de> Content-Language: en-US From: Ahmad Fatoum In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241219_022756_759877_9FDB2CB3 X-CRM114-Status: GOOD ( 19.62 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.whiteo.stw.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-5.1 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: Re: i.MX8/9: question about unused DDR PHY trained CSR board array X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.whiteo.stw.pengutronix.de) Hello Peng, On 30.09.24 08:38, Peng Fan wrote: >> Subject: i.MX8/9: question about unused DDR PHY trained CSR board >> array >> Looking at the DDR setup code for i.MX8M and i.MX9 that you had >> contributed, I am wondering about struct >> dram_cfg_param::ddrphy_trained_csr and the global >> ddrphy_trained_csr array. >> >> struct dram_cfg_param::ddrphy_trained_csr is presumably generated >> by the i.MX DDR tool and it seems populated by all the i.MX8M/9 >> boards in U-Boot. >> >> This struct member is wholly unused though and instead a global >> ddrphy_trained_csr is used. >> >> What I wonder about is whether it's possible for the DDR tool to >> generate a different ddrphy_trained_csr than the default: >> >> 1) If yes, we should drop the global ddrphy_trained_csr and actually >> use >> the board-specific array >> >> 2) If not, we should drop the board-specific array and perhaps ask for >> the DDR tool to be changed >> >> I initially assumed 1) and because all boards supported by barebox had >> a board-specific ddrphy_trained_csr that's identical to the global >> ddrphy_trained_csr, I dropped the unused array[1][2]. >> >> I now have the DDR settings for an i.MX9 LPDDR4 board in front of me >> that has different contents for struct >> dram_cfg_param::ddrphy_trained_csr than the default. >> >> I will inquire how that came about, but in parallel I wanted to ask you if >> this is supposed to happen and to alert you to this issue. > > Thanks for raising this issue. I think board specific csr should be used. > > I will check with DDR TOOL owners on this. Did you hear back in the meantime? Thanks, Ahmad > >> >> The way things are, this is either a bug or a missed space saving >> opportunity for U-Boot. > > Thanks, > Peng. > > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |