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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D8B8C61DB3 for ; Fri, 6 Jan 2023 22:08:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236357AbjAFWIF (ORCPT ); Fri, 6 Jan 2023 17:08:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46688 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235695AbjAFWHl (ORCPT ); Fri, 6 Jan 2023 17:07:41 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4CE2F84BCB; Fri, 6 Jan 2023 14:07:41 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 0669FB81C4A; Fri, 6 Jan 2023 22:07:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 36B8AC433EF; Fri, 6 Jan 2023 22:07:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673042858; bh=c66oe5wybRoqWCFcVW6cGO/BKva+TgCILRvTFkO6oBk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Ro7RTlMO/NV43orzBNYrUksWo3Cn21zSRcKbp3ja98pQN5zPLJ69zVkusrJWvugh1 gjUxwPZHi/LZSKRQ4u+hdFie0EdT0gWLjlF7XfPcCnVSMnA16dFaT5Gho1dirM42HP DqWJ/imEK1/FPEu1iL+wN6dj0eI3OtLvY0MhE9PMmV84JKDJB1UWUT75Hhx9QxMMtv wj2k9URPqM/tXULZ0b/WHmcLFgolO3sSBwbWYImeya38tsuZpMTcTg9VacLXtSz95r N8MCM9X5YuibTPtrg++xmgHGl7VxJLBpPoaxnmlmbcwe1FYYi5XezmxLdow2m97Aj2 /cVI1LRrhnsQA== Date: Fri, 6 Jan 2023 22:07:32 +0000 From: Mark Brown To: William Zhang Cc: Linux SPI List , Broadcom Kernel List , anand.gore@broadcom.com, tomer.yacoby@broadcom.com, dan.beygelman@broadcom.com, joel.peshkin@broadcom.com, f.fainelli@gmail.com, jonas.gorski@gmail.com, kursad.oney@broadcom.com, dregan@mail.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 14/16] spi: bcm63xx-hsspi: prepend: Disable spi mem dual io read op support Message-ID: References: <20230106200809.330769-1-william.zhang@broadcom.com> <20230106200809.330769-15-william.zhang@broadcom.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="EwWYfXXpNT8odNd5" Content-Disposition: inline In-Reply-To: <20230106200809.330769-15-william.zhang@broadcom.com> X-Cookie: Do not fold, spindle or mutilate. Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --EwWYfXXpNT8odNd5 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Jan 06, 2023 at 12:08:06PM -0800, William Zhang wrote: > In general the controller supports SPI dual mode operation but the > particular SPI flash dual io read op switches from single mode in cmd > phase to dual mode in address and data phase. This is not compatible > with prepend operation where cmd and address are sent out through the > prepend buffer and they must use same the number of io pins. >=20 > This patch disables these SPI flash dual io read ops through the mem_ops > supports_op interface when prepend mode is used. This makes sure the SPI > flash driver selects the compatible read ops at run time. This suggests that your prepend mode is attempting to combine incompatible transfers doesn't it? Presumably other devices could generate similar access patterns... --EwWYfXXpNT8odNd5 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmO4m6QACgkQJNaLcl1U h9BPoAf/f3LHS3QMDi/9wy02iBggh+iqTs52FZRHzluvZjiMrEUO67cD8y6jJ1Al dd2+4cgc4J3Sz25wsLKvLuPq7KFehLVAd8n+dUlozQqoVoUBTPqZROzWiavKKfQL j1YJE3voybTFib1zW9zHMbzevln3nsTNq33ZX+Lid6SX3Liei61SDZz2Iw3af6HW hvnIdPlr2OEESnwr4VfnnmGM+ZGJ5jIidWsj0zAuPmb8TT39XqWOmVId0/CM+hFB +WNHNWjHg+wzpp5s2zOJvSl9zUDjWnBJe6LM0cyM9yX9t+syv/atUJzdFDeVr/wW +Lshri95xSSZ11akM/oxAjnSxANB8A== =pZKP -----END PGP SIGNATURE----- --EwWYfXXpNT8odNd5--