From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=185.171.202.116 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793289515; b=N4QbDiGeVzbKuvgwykDJSOBJ+y/XIZvVjSePuvEVmqhDsNR/GcRy9QjxDL/L8DfM7AXw 2mU4E1JDd8FmjReizHar9oBnXNykSoLMhTHFxsBpMbDuGqHEO6tsTDUVrAIOu8lELpk4O zDNBsk1ZowBdsoWfdtEyFaWymlN1u73UK47al2CU0u8dP7JvXmhnWhBmg4S+W8kSfRO1P GHdihgxIOjN6XIq9sVsIk1S5J77ISRYppwmTZAaoSMjWQMRwdY1McEmlu0ZLZACgrb0Il sWK3kh4L1SREY+xnPitqpi5j/J7ITi3bRxjjwjqCZU7ktf8W9wxH0RjdxwJRYX3Azkg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793289515; h=DMARC-Filter:Received:Received:Received:DKIM-Signature:From:To:Cc: Subject:In-Reply-To:References:User-Agent:Date:Message-ID: MIME-Version:Content-Type:Content-Transfer-Encoding: X-Last-TLS-Session-Version; bh=V1AcEN3/F7WCrixuUIKybsNv5HdIIcQfV8dHDzHK5Dc=; b=VIdoBK823UCl07LLDpg2rSV0RJW7j0k10tHsBWaIm5jPV6Serk+VufM9VabjotZ9OVgH vOlbazdBk6wEy4wjysrqO6y63QOrwtFa0O0nkZ9Om1dugc6nvkDOWtv60iQBGYZxznX1a s0Iu0JGGmS8n+pzgo/6ZpcY/YQ7cp3Ll9/Ifx1srrWMzldfZEl0CR0lPVOA8c11uV4CJr H7UsT7gqQy6jcb99EuMkhVODv0DjX18Uhf+KDwHwlFSAZSONRsBXmW8HaYV6Y//YYN2YM hiaNEoy3AU0CkPeQIT7USZbVmXIRa914NBAEUvbu3DrlQmwFWWV5/M5PVx1y88bRROw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass header.d=bootlin.com header.i=@bootlin.com header.a=rsa-sha256 header.s=dkim header.b=EtZNgrCN; arc=none smtp.remote-ip=185.171.202.116 Received: from smtpout-04.galae.net (smtpout-04.galae.net [185.171.202.116]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8BA9A606A31A for ; Thu, 29 Oct 2026 15:58:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 8BA9A606A31A Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=bootlin.com header.i=@bootlin.com header.a=rsa-sha256 header.s=dkim header.b=EtZNgrCN Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-04.galae.net (Postfix) with ESMTPS id BA740C49F4A; Thu, 29 Oct 2026 15:59:33 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 450C86076B; Thu, 29 Oct 2026 15:58:31 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 09C2D1032910A; Thu, 29 Oct 2026 16:58:18 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1793289504; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=V1AcEN3/F7WCrixuUIKybsNv5HdIIcQfV8dHDzHK5Dc=; b=EtZNgrCNIU0luOGdzO+em8UiYQvCgbSDaFgUTCvPjSTPJwbkszVmGSg4IYnP0diUE8N229 ans4HJ+68rYQLYLGW2trcnbOGGXuKYc2Qr9sGrZ8mU6e5pDy1PCBQFwthZWb+GAfEZqu3C aNpu0sxh3cdyrwX6EBGPIL03wo1db9eOcgAeiiqRdhJB5MaU7gaHrXnH85IVaeXwdhB5Cf cZmu1NSwv7bPc/lCcLRQsw9raSagx6XBVDyZnjdHnglOqlWPd+xTzaMXqA76Enm887oZZf +xxf7Roub1zJ0d2W9wGQ/IiXaVaVd2EIqUWQGhsJk/Pab5d5cqWQIBV6PwBMWA== From: Miquel Raynal To: Mikhail Kshevetskiy Cc: Richard Weinberger , Vignesh Raghavendra , Tudor Ambarus , Martin Kurbanov , Takahiro Kuwano , Cheng Ming Lin , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, Andreas Gnau Subject: Re: [PATCH RESEND v5 3/3] mtd: spinand: repeat reading in regular mode if continuous reading fails In-Reply-To: <20250917215401.19132-4-mikhail.kshevetskiy@iopsys.eu> (Mikhail Kshevetskiy's message of "Thu, 18 Sep 2025 00:54:01 +0300") References: <20250917215401.19132-1-mikhail.kshevetskiy@iopsys.eu> <20250917215401.19132-4-mikhail.kshevetskiy@iopsys.eu> User-Agent: mu4e 1.12.12; emacs 30.2 Date: Thu, 29 Oct 2026 16:58:18 +0100 Message-ID: <87mrrwebxh.fsf@bootlin.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Last-TLS-Session-Version: TLSv1.3 Hi Mikhail, On 18/09/2025 at 00:54:01 +03, Mikhail Kshevetskiy wrote: > Continuous reading may result in multiple flash pages reading in one > operation. Unfortunately, not all spinand controllers support such > large reading. They will read less data. Unfortunately, the operation > can't be continued. > > In this case: > * disable continuous reading on this (not good enough) spi controller > * repeat reading in regular mode. > > Signed-off-by: Mikhail Kshevetskiy This patch unfortunately breaks continuous reads on my boards without dirmap support. The fact that they do not have dirmap support does not mean they are not capable of keeping CS asserted, these are two orthogonal hardware capabilities and it seems that we cannot easily discover it at run time. I recently had a similar issue with a "powerful" controller (cadence-qspi) with dirmap support. The fact that controllers will or will not spuriously assert their chip select is not discoverable either. As a result I created a spi-mem capability to flag this impossibility, which disables continuous reads. I will send a patch to revert this commit (keeping the previous ones) and another one to flag the Airoha controller as not having full control over its CS. Thanks, Miqu=C3=A8l