From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 23A25274B39; Sun, 16 Nov 2025 21:45:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763329510; cv=none; b=Wl7FKHrrr3vOLHKTmLSu6OW7LcCUoC4Vu8xiMxO/yLYkiXeYCxImyiicSNfB8dSmlOX+9LIBmapw01KmQ2S7dgMhX4GgyNtbipnOnvmAGZWCFPhYrQSzLFwBXcLbZBqHQLjbQ5gwU7b9lZybgAN6MakuZWoT/dZtGmKMSUf6/AE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763329510; c=relaxed/simple; bh=OFcKRCVjubrxzsJleuthq3OzYLRHIbcDrAF37egFXTk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=XissR7C/Bu80mACohmChYX8WPes8dfurqV6hyaeldsdhEu8aJ8id3kjhfqGZtxhjLTZlQd6Ld/4TOAez0ox2HZher5ne76DPhVkYQz5tQo47zlIZENoOikPj+53yWfzszBVLVWKIEMtjB+v1Hw2KX1b2zXnzHYdZCygvxUUgikY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jf2oeuyl; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="jf2oeuyl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6410DC116D0; Sun, 16 Nov 2025 21:45:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1763329505; bh=OFcKRCVjubrxzsJleuthq3OzYLRHIbcDrAF37egFXTk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jf2oeuylhF7xDEtEkCnG3eX2TR4cafRNZCBiEJegX44Zz68WV45R/3jDRQ/CeCwTs J0PrHZoIapLPYpwIseg12m5MpyR60L8UT6paWP6zi0wVfXohPnVTqCPVvGP6jk2pb5 H5sAYtqu4qRtVypeuv40mIEl4a3DWkTVXgqHExfuainH4+0lVm8SAh7IuBdELCjkcS xrt1nXRwXNg1Nz1ORknq88gKVRvJCBOeO+EzgDjNzCnZvzmeX/lCy4tN6YcvM8Ar6o OSplpV89BcsviGz8zmGJBP9d9KqOi4CUNDc7zx0JM5VRw/iF3yeuw19p6i9iNRzLJu lrYDlz2svjaIw== Received: by finisterre.sirena.org.uk (Postfix, from userid 1000) id 2937D1ACCC98; Sun, 16 Nov 2025 21:45:02 +0000 (GMT) Date: Sun, 16 Nov 2025 21:45:02 +0000 From: Mark Brown To: Hang Zhou <929513338@qq.com> Cc: jonas.gorski@gmail.com, linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] spi: bcm63xx: fix premature CS deassertion on RX-only transactions Message-ID: References: Precedence: bulk X-Mailing-List: linux-spi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="NAmoIJdmrm/O9qw9" Content-Disposition: inline In-Reply-To: X-Cookie: marriage, n.: --NAmoIJdmrm/O9qw9 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Mon, Nov 17, 2025 at 01:08:35AM +1100, Hang Zhou wrote: > Fix this by writing 0xff dummy bytes into the TX FIFO for RX-only > segments so that the number of bytes written to the FIFO matches the > total message length seen by the controller. Why 0xff? The core's _MUST_TX handling writes 0x00 which feels a bit more natural. Given that this is PIO rather than DMA the memset_toio() is going to be better than using the core (which is more for DMA). --NAmoIJdmrm/O9qw9 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmkaRdoACgkQJNaLcl1U h9Bbmwf/QkvNS2zKL1I1vPg7PN4GS7OKvQ0CSxyK2LpnAe+YDzWu7a/H5jKBipcS SyMJ+C87vg8qWSJuDwMmNmt65W3nT2AaUIyxGV8lpFRDiB+gx144F5rwWTWDFclv O6kZXuMw2CNHrW/z1vXVyAUoan0OpoAcGyyg/9lFLViCBkSVJj3oke4eBaUrYHKU 3rhSwhoz9zY3dS4Kwz5iNrzKcrGV3b4VFWWzHywj6hNYxCYg+ylK4QkNKNrOtTDd Td3qOjy+/Oz/mujjv2JoXX1cmHZkCu7ATEUEkxChAEyh5lHzCNkBUA2KyS3ZlSBP wek9eNeZCuZFdKTjikDe+XQZkSGtKw== =RcUq -----END PGP SIGNATURE----- --NAmoIJdmrm/O9qw9--