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=1792665909; b=5W1JIFU9s1NJfdUzcQ8QtE8kNUsCQBZcgZaw+6QgKaIPg5/6zPNXs0Of2d6rCSD3LLMV TWtfNY7ertSBSb7yaYcHptZO5xnpLI9Gp6FauwPGkdhs1PkWqNecX2iENjMpLWR5XU6FP QZZCmSLL2MmCw9aXLc/5eda6KhWLDpu7bfIymGIdmuDTSUtnCp52GEfoAOei2srkaAf87 0Bg0iKjgydSgO+PUIRI6RSrDXH8uTshQPOgJUO/3p+XBV2HlclJo4Fpr0gfgH3Gbqlyvq o7MjbOa5QM0gaO8p/LbkbfsFVbVS+5l8ip/G0/sHIo3IDHQxjsRNt9DP2GUCQ72HNqw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792665909; 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:X-Last-TLS-Session-Version; bh=dCrqHqvHupUGX9Yb0K8VNQTC2XGQqllo1XVHZ6S5VJU=; b=DPqYxuGG1GAiiV49rfcP/r/mLJZw2HbrzdDkgkfldRqrXNFHNgdRU5tYP455ZJBb8Z0+ QwlMh/AjOhT9gbLXo4+RLL44UdQ0VLDKLLmfDkW60inUDyAq8p0QaQrmHPqmQXb3l+ddl Liz8Pk73o0piEF7aPJrD27OuVbtFzV4cOQLTZzm66Jn3IAaAtUOVf+vLS9hvSqzzoDpmJ /NT+/yA/G5BDD0XiniRnlxXbyAJYno7d33QMj0tx3ZcyteYdLaktJUbJFRTZBKbuqE3Rf yFk776FU6K86JQbTS4D5wpz9pE7+dvX1mLlFi4AKkWkaSqqfqHVw25xWPdmxIKj7Bqw== 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=ONl86gl0; 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 3CE9B606A31B for ; Thu, 22 Oct 2026 10:45:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 3CE9B606A31B 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=ONl86gl0 Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-04.galae.net (Postfix) with ESMTPS id DA5D7C58473; Thu, 22 Oct 2026 10:46:05 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 67EB460360; Thu, 22 Oct 2026 10:45:06 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id BE36910328E44; Thu, 22 Oct 2026 12:45:03 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1792665905; h=from:subject:date:message-id:to:cc:mime-version:content-type: in-reply-to:references; bh=dCrqHqvHupUGX9Yb0K8VNQTC2XGQqllo1XVHZ6S5VJU=; b=ONl86gl0EqNN7/oWlBAo2Q48bwtbfFr8LrXVh74yH/RgfWgm6cQfOWRRu/zzZOoyPmBxCo w7tdSMwRh1wXWyE6P4gTbV1e7qTwIAcy6WFYcKYRIluCJcI7CUtiX4LH7s8xo1IkuMkcyb 10JI26l2sVA49wX6Hcw7V4c2mUNOPsJ5ooN92frULR5ErhU4PZ4hicKOunWIPlVApR/OU2 6oWGTb7GKXT7RGNQeP839zonHGpwxujfkJ7C2Tjq99tyz8RRaqdJ/aKEftIioHHglYY/Tl b9JdFn5fyUY2BObOjH5w4VhGE2hDgYlCpmPr9o0xfp9hGxzqXCO8tbJktVTomg== From: Miquel Raynal To: Changhuang Liang Cc: Pratyush Yadav , Michael Walle , Takahiro Kuwano , Mark Brown , Richard Weinberger , Vignesh Raghavendra , linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org Subject: Re: [PATCH v1 2/4] mtd: spi-nor: Support mixed 1S-xD-xD DTR protocols in spi_nor_spimem_setup_op() In-Reply-To: <20261022102614.75696-3-changhuang.liang@starfivetech.com> (Changhuang Liang's message of "Thu, 22 Oct 2026 03:26:12 -0700") References: <20261022102614.75696-1-changhuang.liang@starfivetech.com> <20261022102614.75696-3-changhuang.liang@starfivetech.com> User-Agent: mu4e 1.12.12; emacs 30.2 Date: Thu, 22 Oct 2026 12:45:03 +0200 Message-ID: <875wyuqaj4.fsf@bootlin.com> X-Mailing-List: linux-spi@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 X-Last-TLS-Session-Version: TLSv1.3 On 22/10/2026 at 03:26:12 -07, Changhuang Liang wrote: > Currently spi_nor_spimem_setup_op() sets all four phases (cmd, addr, > dummy, data) to DTR whenever spi_nor_protocol_is_dtr(proto) is true. > This is too coarse: the 1S-xD-xD DTR protocols (1_1_1_DTR, 1_2_2_DTR, > 1_4_4_DTR, 1_8_8_DTR) send the command phase in STR on a single line, > and only the address, dummy and data phases in DTR. SPIMEM supports > such mixed DTR modes. > > Split the handling: > > - For SNOR_PROTO_8_8_8_DTR, keep the existing behavior: set all > phases to DTR and use a 2-byte opcode (opcode + extension). > > - For the other DTR protocols, set the command phase to STR and only > the address, dummy and data phases to DTR. Double op->dummy.nbytes > since DTR transfers 2 bytes per clock cycle, matching how the dummy > cycle count is specified for these protocols. > > No in-tree flash currently declares SNOR_HWCAPS_READ_1_x_x_DTR, so > this is not a bug fix but preparation for enabling these protocols. > A follow-up patch will enable 1S-4D-4D for the MX66L1G45G. The > 8D-8D-8D path is unchanged. > > Signed-off-by: Changhuang Liang > --- > drivers/mtd/spi-nor/core.c | 21 ++++++++++++++------- > 1 file changed, 14 insertions(+), 7 deletions(-) > > diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c > index 90524c58602e..43e506e728ab 100644 > --- a/drivers/mtd/spi-nor/core.c > +++ b/drivers/mtd/spi-nor/core.c > @@ -97,13 +97,7 @@ void spi_nor_spimem_setup_op(const struct spi_nor *nor, > if (op->data.nbytes) > op->data.buswidth = spi_nor_get_protocol_data_nbits(proto); > > - if (spi_nor_protocol_is_dtr(proto)) { > - /* > - * SPIMEM supports mixed DTR modes, but right now we can only > - * have all phases either DTR or STR. IOW, SPIMEM can have > - * something like 4S-4D-4D, but SPI NOR can't. So, set all 4 > - * phases to either DTR or STR. > - */ > + if (proto == SNOR_PROTO_8_8_8_DTR) { > op->cmd.dtr = true; > op->addr.dtr = true; > op->dummy.dtr = true; > @@ -115,6 +109,19 @@ void spi_nor_spimem_setup_op(const struct spi_nor *nor, > ext = spi_nor_get_cmd_ext(nor, op); > op->cmd.opcode = (op->cmd.opcode << 8) | ext; > op->cmd.nbytes = 2; > + } else if (spi_nor_protocol_is_dtr(proto)) { > + /* > + * 1S-xD-xD protocols: the opcode is sent in STR on a single > + * line, only the address, dummy and data phases are DTR. The > + * opcode stays 1 byte (no command extension). > + */ > + op->cmd.dtr = false; > + op->addr.dtr = true; > + op->dummy.dtr = true; > + op->data.dtr = true; Still to coarse IMHO. What about xS-xS-xD? As mentioned in the spi controller patch you must make sure these are refused if they are not supported by your controller because SPI NAND at least allow them (and I believe SPI NOR might as well)?. > + > + /* 2 bytes per clock cycle in DTR mode. */ > + op->dummy.nbytes *= 2; > } > > if (proto == SNOR_PROTO_8_8_8_DTR && params->flags & SNOR_F_SWAP16)