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 710E6168C5 for ; Mon, 8 May 2023 10:57:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CBFEEC433AA; Mon, 8 May 2023 10:57:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1683543452; bh=d9u7KixYQFLZpMdHU5J7ywXcNX2AquLzyQtEbBSO+OQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aKRQAEp6waUPHqjL1rW20bWUk5njDnXjugk6xT0Uc8dxAWcTBu6U/QHpqblYgGhN3 gdd+PNAUoO01/c1+NuA4W5QPro/bplFsnrot9cnWAGYsC8V5byzOExxd1odOBys65K DlJt3u8HmgR3YzbHTjCWmAYzF1OhKOIwwUNZFLhk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jonathan Cameron , Dave Jiang , Alison Schofield , Dan Williams Subject: [PATCH 6.3 095/694] cxl/port: Scan single-target ports for decoders Date: Mon, 8 May 2023 11:38:50 +0200 Message-Id: <20230508094435.600164130@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230508094432.603705160@linuxfoundation.org> References: <20230508094432.603705160@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Dan Williams commit 7bba261e0aa6e8e5f28a3a3def8338b6512534ee upstream. Do not assume that a single-target port falls back to a passthrough decoder configuration. Scan for decoders and only fallback after probing that the HDM decoder capability is not present. One user visible affect of this bug is the inability to enumerate present CXL regions as the decoder settings for the present decoders are skipped. Fixes: d17d0540a0db ("cxl/core/hdm: Add CXL standard decoder enumeration to the core") Reported-by: Jonathan Cameron Link: http://lore.kernel.org/r/20230227153128.8164-1-Jonathan.Cameron@huawei.com Cc: Reviewed-by: Jonathan Cameron Reviewed-by: Dave Jiang Reviewed-by: Alison Schofield Link: https://lore.kernel.org/r/168149845130.792294.3210421233937427962.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman --- drivers/cxl/core/hdm.c | 5 +++-- drivers/cxl/port.c | 18 +++++++++++++----- 2 files changed, 16 insertions(+), 7 deletions(-) --- a/drivers/cxl/core/hdm.c +++ b/drivers/cxl/core/hdm.c @@ -92,8 +92,9 @@ static int map_hdm_decoder_regs(struct c cxl_probe_component_regs(&port->dev, crb, &map.component_map); if (!map.component_map.hdm_decoder.valid) { - dev_err(&port->dev, "HDM decoder registers invalid\n"); - return -ENXIO; + dev_dbg(&port->dev, "HDM decoder registers not implemented\n"); + /* unique error code to indicate no HDM decoder capability */ + return -ENODEV; } return cxl_map_component_regs(&port->dev, regs, &map, --- a/drivers/cxl/port.c +++ b/drivers/cxl/port.c @@ -66,14 +66,22 @@ static int cxl_switch_port_probe(struct if (rc < 0) return rc; - if (rc == 1) - return devm_cxl_add_passthrough_decoder(port); - cxlhdm = devm_cxl_setup_hdm(port, NULL); - if (IS_ERR(cxlhdm)) + if (!IS_ERR(cxlhdm)) + return devm_cxl_enumerate_decoders(cxlhdm, NULL); + + if (PTR_ERR(cxlhdm) != -ENODEV) { + dev_err(&port->dev, "Failed to map HDM decoder capability\n"); return PTR_ERR(cxlhdm); + } + + if (rc == 1) { + dev_dbg(&port->dev, "Fallback to passthrough decoder\n"); + return devm_cxl_add_passthrough_decoder(port); + } - return devm_cxl_enumerate_decoders(cxlhdm, NULL); + dev_err(&port->dev, "HDM decoder capability not found\n"); + return -ENXIO; } static int cxl_endpoint_port_probe(struct cxl_port *port)