From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794332831; b=ojoci3wxxKLi6eafe1JD8V9yIpKhd61VZo7/OVj9q6EcV57hiLRzexBYUSGo9R9b3DF1 PEpbOjrb/m4LChPB/pdE0M2Y0Wjd9AVCGsx2D0/f0vNEqQT2faOHSX60S9S2mGRS8hA4j OLD6eB8WexFwGAALMZDsn396TPp2bHenO9jReflQzxclXy2NGL/tL42fsg50v99lQDiRc MMqK6cpqJPDP3cOiMaTifjZCP+kteNF5jyICYUF4Ud1lEv94ZvxKD9igHoDLtthNXs4Fn SVW++Zg3SydMIWeodoPtwEQJfeltG/wXSswiSlIGZu4K8kmR/4vMlinqbnADSeAXaEQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794332831; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=GAGZwdCIJ6oI01UrruZjJsCbx0Rq3e3ya8oMNd1r2UU=; b=Isph36z5aXML1uxHUxgOM63990AzTs5q0JerC0jIwHpydnqlNdcOk5KSizCNvLAmZCY0 bfTeO/GY2Ofd32ZD8tkqHZoK5wAysuANf4tbBmyeUnpdj8Q1m5L1bnLNruhdRn9eqTRIA bv3U5I1MfebU3eZ0MdmtjxeX/cMmaBhubctDPoaxoIK05AUBAhq9dgyPDMyxjgpy+tx8y 3eK4D1JO1oKI9vD0q7jR07JYpW/DQipZiUb330Qe3X+l0kSGRq251DAqPZEiTuLLDFpMw LbC2ZObU8gOp2NDOM8E/ibJACZclrx483od8IPC2Wq6MnJPS9xN+bdil5zHSEL1EbjA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Sqt4Yzga; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7B6A8606A31C for ; Tue, 10 Nov 2026 17:47:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Sqt4Yzga Received: by smtp.kernel.org (Postfix) with ESMTPSA id EFB851F008A7; Tue, 10 Nov 2026 17:47:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794332831; bh=GAGZwdCIJ6oI01UrruZjJsCbx0Rq3e3ya8oMNd1r2UU=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=Sqt4YzgapDpPI3mYrDUIhVM2T2mWaRO5wfeCictMioJni5qLevTVT0MyLJWoZARpR TjiNUsrZJv4om8oz6mR/0zk9jBJglJYGRyRkx2cxOKmeKreBvbmWqOyR1MR2itp+jU wy6fRnUQpTWsWtWwgyzzz2ZpO2y3i5OWAwG5Z8yJbUZiiFeJuBWXCxQpvyelmU9DrA D7mcDO1GZGbS4qrSS1sA8FXuLHp8Bwy7WzCcst+XaAruRdKm9X8+sy0DyWF+uiMZXb 65F/IBDqnnmjWMf47fxWSlIB0CcrKOwJ+LR/mYGnJ+queOlEdZBccFEIlv1w/lWbSO i1rNUkZKEdjkw== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v4 4/4] dmaengine: switchtec-dma: add pmon sysfs attributes Reply-To: sashiko-reviews@lists.linux.dev To: "Logan Gunthorpe" , dmaengine@vger.kernel.org Cc: vkoul@kernel.org, Frank.Li@kernel.org In-Reply-To: <20261110173137.623764-5-logang@deltatee.com> References: <20261110173137.623764-1-logang@deltatee.com> <20261110173137.623764-5-logang@deltatee.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 10 Nov 2026 17:47:10 +0000 X-Mailing-List: dmaengine@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Thank you for your contribution! Sashiko AI review found 1 potential issue to consider: - [Low] dmaengine: switchtec-dma: multi-line menu output in latency_selector_show() -- commit a610541f39faa290edb39d9134f3a2df55bdae1a Author: Logan Gunthorpe dmaengine: switchtec-dma: add pmon sysfs attributes This commit adds a "switchtec-pmon" sysfs attribute group to expose Switchtec DMA performance monitoring registers per channel. > diff --git a/drivers/dma/switchtec_dma.c b/drivers/dma/switchtec_dma.c > index 1ebe17095c61a..774b418330ed7 100644 > --- a/drivers/dma/switchtec_dma.c > +++ b/drivers/dma/switchtec_dma.c [ ... ] > @@ -1215,8 +1222,274 @@ static const struct attribute_group switchtec_con= fig_group =3D { > .attrs =3D switchtec_config_attrs, > }; > =20 [ ... ] > +static ssize_t latency_selector_show(struct device *dev, > + struct device_attribute *attr, char *page) > +{ > + struct switchtec_dma_chan *swdma_chan; > + struct chan_fw_regs __iomem *chan_fw; > + u32 lat =3D 0; > + int len; > + > + CLASS(dmaengine_chan_from_dev, c)(dev); > + > + if (!c) > + return -ENODEV; > + > + swdma_chan =3D container_of(c, struct switchtec_dma_chan, dma_chan); > + chan_fw =3D swdma_chan->mmio_chan_fw; > + > + rcu_read_lock(); > + if (!rcu_dereference(swdma_chan->swdma_dev->pdev)) { > + rcu_read_unlock(); > + return -ENODEV; > + } > + > + lat =3D readl(&chan_fw->perf_latency_selector); > + rcu_read_unlock(); > + > + len =3D sysfs_emit(page, > + "To select a latency type, write the type number\n"); > + len +=3D sysfs_emit_at(page, len, "(1 ~ 5) to latency_selector\n\n"); > + > + len +=3D sysfs_emit_at(page, len, "Latency Types:\n"); > + len +=3D sysfs_emit_at(page, len, "(1) SE Fetch latency"); > + if (lat & SWITCHTEC_LAT_SE_FETCH) > + len +=3D sysfs_emit_at(page, len, " (*)\n"); > + else > + len +=3D sysfs_emit_at(page, len, "\n"); > + > + len +=3D sysfs_emit_at(page, len, "(2) VDM latency"); > + if (lat & SWITCHTEC_LAT_VDM) > + len +=3D sysfs_emit_at(page, len, " (*)\n"); > + else > + len +=3D sysfs_emit_at(page, len, "\n"); > + > + len +=3D sysfs_emit_at(page, len, "(3) Read Immediate latency"); > + if (lat & SWITCHTEC_LAT_RD_IMM) > + len +=3D sysfs_emit_at(page, len, " (*)\n"); > + else > + len +=3D sysfs_emit_at(page, len, "\n"); > + > + len +=3D sysfs_emit_at(page, len, "(4) SE Processing latency"); > + if (lat & SWITCHTEC_LAT_SE_PROCESS) > + len +=3D sysfs_emit_at(page, len, " (*)\n"); > + else > + len +=3D sysfs_emit_at(page, len, "\n"); > + > + len +=3D sysfs_emit_at(page, len, "(5) FW NP TLP latency"); > + if (lat & SWITCHTEC_LAT_FW_NP) > + len +=3D sysfs_emit_at(page, len, " (*)\n"); > + else > + len +=3D sysfs_emit_at(page, len, "\n"); > + > + return len; > +} [Severity: Low] Does latency_selector_show() violate the sysfs one-value-per-file rule? Reading latency_selector emits multi-line usage instructions and a numbered menu marked with "(*)", while latency_selector_store() expects a single integer from 1 to 5 via kstrtoint(), so the output cannot be parsed as a single value or written back to the attribute. Could latency_selector expose a single value (or a single-line space-separated list of tokens with brackets around the active selection, documented under Documentation/ABI/), or move human-oriented menus to debugfs? --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261110173137.6237= 64-1-logang@deltatee.com?part=3D4