From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Tue, 01 Apr 2025 13:41:46 +0200 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 1tza02-006yVC-2v for lore@lore.pengutronix.de; Tue, 01 Apr 2025 13:41:46 +0200 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 1tza02-00006o-AZ for lore@pengutronix.de; Tue, 01 Apr 2025 13:41:46 +0200 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=FnsJZlMz1demvnV6jnQfEOJ6Tdf57GveTBxsEiy7e78=; b=avTyjjKXkgznCl0B6ftrr6GVtt SkSJEIdmo8wze9sJ2+na9+OU6nZBCwBUA6zBto3jkjAfXmtvg2CZjloky9VtOpRyCYm8Z1LJTwniA WMi80cCIhAEgNrr2a0nKfCkwasafjQeCp4z8sJpceukKHk5CbJqzigB4NR/N1d6Ml6foIWLbnKQsK jM5SJ+qr8uQ0PxbhlTDKwkqCTIGTRtRtSMIFVy/ZsnV/mzrNEui6Ud4sV5l2r8pxz9vj1uXT90Poj qp26fkK2rY5yLiypLNrjpX1oRwu5lIrtc3JVqSwRx0uZkb81Hq9zU4XFrThKwC5yRkTbZre3s1jr7 GH/C+Y1Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.1 #2 (Red Hat Linux)) id 1tzZzT-00000002ofK-3uVN; Tue, 01 Apr 2025 11:41:11 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.98.1 #2 (Red Hat Linux)) id 1tzZzP-00000002oeW-207W for barebox@lists.infradead.org; Tue, 01 Apr 2025 11:41:09 +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 1tzZzO-0008RH-6C; Tue, 01 Apr 2025 13:41:06 +0200 Message-ID: <72a9de59-613c-4c73-9bbd-b10df44d6f55@pengutronix.de> Date: Tue, 1 Apr 2025 13:41:05 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird To: Oleksij Rempel Cc: barebox@lists.infradead.org References: <20250331122918.564304-1-o.rempel@pengutronix.de> <6f67de1f-b159-4190-bd31-ed2ef990f290@pengutronix.de> Content-Language: en-US, de-DE, de-BE From: Ahmad Fatoum In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250401_044107_512389_EFEB28E0 X-CRM114-Status: GOOD ( 21.99 ) 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=-5.8 required=4.0 tests=AWL,BAYES_00,DIET_1, 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: [PATCH v1] spi: add STM32F7 QSPI controller driver 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 Oleksij, On 4/1/25 11:05, Oleksij Rempel wrote: > On Tue, Apr 01, 2025 at 10:53:44AM +0200, Ahmad Fatoum wrote: >> Hello Oleksij, >> >> On 3/31/25 14:29, Oleksij Rempel wrote: >>> From: Ahmad Fatoum >>> >>> Introduce support for the STM32F7 QSPI controller, compatible with >>> "st,stm32f469-qspi". >>> >>> Validated on STM32MP133-based MECT1S r1 board, which includes an >>> F7-compatible QSPI peripheral >>> >>> Signed-off-by: Ahmad Fatoum >>> Signed-off-by: Oleksij Rempel >>> --- >> >> [snip] >> >>> +static int stm32_qspi_get_mode(u8 buswidth) >> >> Is this ever called with a buswidth > 1? I think the spi_mem core in >> barebox never uses higher buswidths. Given that you are adding QSPI >> support, you will surely want to see quad buswidth actually working, >> right? :D > > Sure :) I get it - every maintainer dreams of getting the most out of > each patch, and full QSPI support with quad buswidth would definitely be > nice to have. > > But with this patch, we're going from “doesn't work at all” to “works, > just not at full speed yet.” That’s already a big step forward, > especially for bring-up and flashing use cases. I agree that it's a considerable improvement. Thanks for putting time into making it work. > If we judged everything in Barebox by full performance, we’d probably > have to drop most of the networking drivers too - since Barebox usually > isn’t about maxing out throughput anyway ;) Let's get TCP merged before going there. :D > So yes, proper quad support would be great - but for now, this patch > gets us something working, and that’s a solid starting point. The thing is there are a number of QSPI drivers already and there's still no exercising of higher buswidths. I don't have any projects currently that use SPI-NOR with a higher bus width, so the only thing I can do is raise some awareness of the limitation. ;) Cheers, Ahmad > > Best Regards, > Oleksij -- 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 |