From nobody Sat Nov 30 05:36:58 2024 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 E54B41AB6FC; Wed, 11 Sep 2024 15:26:30 +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=1726068391; cv=none; b=Yrebt/BSfRiVkxXOghIzUpl5g0X5D/yjgQ8c5TvQFdFz6Q9shWwUrngEYLNoszT37+E5jwd5ofo3fjAPAOGxAow4DQG5haC5hE5sz0BroIolF2fQsjz69FR+wQZ6/dE6dIIQldmwJL5XDYztZ2GOpEK/UxfGzvWswz0Ho0o3Ucw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726068391; c=relaxed/simple; bh=Fs0tboqjW+PVHnmBXKKyJdbjGTmxaZZIL6+StRrdsRc=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=bI6AC3iDyxwaXdP8m4RJBPTXMS4n9MJLsOrBj86/hLrgUMAZWoHcLOcodr2D7LUuESLCNLayzrFQgOfTxUnJPnc48fpSmfdG2ABAl2bbE0n7vdEX4rHJI9URQaQnrjSoWGcAkKs9fMXYVIUAKlWFr2wUXiNrUxINaz/xdVYw2TI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=f24PDyL+; 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="f24PDyL+" Received: by smtp.kernel.org (Postfix) with ESMTPS id 8FFBEC4CED4; Wed, 11 Sep 2024 15:26:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1726068390; bh=Fs0tboqjW+PVHnmBXKKyJdbjGTmxaZZIL6+StRrdsRc=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=f24PDyL+zk9rQlLKThjjyQPvssGwnv3+9oCw/KlEAt8DauIOUh3l/CLTcfTnFZrw8 8Gn6VLX3Axial3Cw6vDRjq1mQpaNNdaz65X2Jkmkv//2ej/0P1yN4QlpngkL9F/NSe ijvVKnMA9J6AcJloeRufKf/my+5LuGQyk6O4DX7vD2Cpwq2pNsxjuZGiQhQtFM3i+2 apV4RXSTVQbHVDCTKJybIfFeq73o+9nteSwQq0qx7GXuf8xBKf0AwA4+DpX6UX5dB5 W0Cu0murF5Wy8JNVqEAqhlp0qwKyPcibMLvXfaJFWRmT97hiWXmcd9qVHMont9ML/1 g5BAiySUUr0tg== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 82ABBEE57C1; Wed, 11 Sep 2024 15:26:30 +0000 (UTC) From: Manivannan Sadhasivam via B4 Relay Date: Wed, 11 Sep 2024 20:56:29 +0530 Subject: [PATCH v7 4/4] PCI: qcom: Add RX lane margining settings for 16.0 GT/s Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20240911-pci-qcom-gen4-stability-v7-4-743f5c1fd027@linaro.org> References: <20240911-pci-qcom-gen4-stability-v7-0-743f5c1fd027@linaro.org> In-Reply-To: <20240911-pci-qcom-gen4-stability-v7-0-743f5c1fd027@linaro.org> To: Richard Zhu , Lucas Stach , Lorenzo Pieralisi , =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= , Rob Herring , Bjorn Helgaas , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , Jingoo Han , Chuanhua Lei , Marek Vasut , Yoshihiro Shimoda , Pratyush Anand , Thierry Reding , Jonathan Hunter Cc: linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, imx@lists.linux.dev, linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-arm-msm@vger.kernel.org, abel.vesa@linaro.org, johan+linaro@kernel.org, Shashank Babu Chinta Venkata , linux-tegra@vger.kernel.org, Manivannan Sadhasivam X-Mailer: b4 0.14.1 X-Developer-Signature: v=1; a=openpgp-sha256; l=5602; i=manivannan.sadhasivam@linaro.org; h=from:subject:message-id; bh=uwqmrdhg0JidfcFTkMSZUh/KB9Ztn0wyucNCKAvoYRU=; b=owEBbQGS/pANAwAKAVWfEeb+kc71AcsmYgBm4bajR3CQi0dab9hbLx+zgTmNgaDe6uJXdKNhw IW7Gv+EqZuJATMEAAEKAB0WIQRnpUMqgUjL2KRYJ5dVnxHm/pHO9QUCZuG2owAKCRBVnxHm/pHO 9S1GCACMX0WRpxGuWrzRU7hQrxgiBbElSht9W4cnKwkh5ro1yf2JvEfO4PtA5fsNsh8SMi/u/Os l4aiB40uUcMWsWpHegjSJKp+T05js5x6Nx5nkWhJNE4Gq6WmrDZxNVlIyQ89EVIJ3OVjX2Bc53z MdkKa9H5p7jMl2xK1fYbi2/QWsHpOfRJCaFq8fUjkRzrb/oDmG+N05W6nlTGJ1UKvjh0a5QWBjt juu/TcLAknZyivCnOGXXeZywT9Ix6lI6MsepCr5FjhjMsHZbzycGbH5+04dHLkVGzVWVqb0qyoa 0eWz5wg/cPsBy82ICOZzTDT+dY5Kc1ZAaOhSfx7ZPz1yMdRR X-Developer-Key: i=manivannan.sadhasivam@linaro.org; a=openpgp; fpr=C668AEC3C3188E4C611465E7488550E901166008 X-Endpoint-Received: by B4 Relay for manivannan.sadhasivam@linaro.org/default with auth_id=185 X-Original-From: Manivannan Sadhasivam Reply-To: manivannan.sadhasivam@linaro.org From: Shashank Babu Chinta Venkata Add RX lane margining settings for 16.0 GT/s (GEN 4) data rate. These settings improve link stability while operating at high date rates and helps to improve signal quality. Signed-off-by: Shashank Babu Chinta Venkata Reviewed-by: Manivannan Sadhasivam [mani: dropped the code refactoring and minor changes] Tested-by: Johan Hovold Signed-off-by: Manivannan Sadhasivam Reviewed-by: Johan Hovold --- drivers/pci/controller/dwc/pcie-designware.h | 18 ++++++++++++++++ drivers/pci/controller/dwc/pcie-qcom-common.c | 31 +++++++++++++++++++++++= ++++ drivers/pci/controller/dwc/pcie-qcom-common.h | 1 + drivers/pci/controller/dwc/pcie-qcom-ep.c | 4 +++- drivers/pci/controller/dwc/pcie-qcom.c | 4 +++- 5 files changed, 56 insertions(+), 2 deletions(-) diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/con= troller/dwc/pcie-designware.h index 7e3a9632fbe8..da9b8f26636c 100644 --- a/drivers/pci/controller/dwc/pcie-designware.h +++ b/drivers/pci/controller/dwc/pcie-designware.h @@ -210,6 +210,24 @@ =20 #define PCIE_PL_CHK_REG_ERR_ADDR 0xB28 =20 +/* + * 16.0 GT/s (Gen 4) lane margining register definitions + */ +#define GEN4_LANE_MARGINING_1_OFF 0xB80 +#define MARGINING_MAX_VOLTAGE_OFFSET GENMASK(29, 24) +#define MARGINING_NUM_VOLTAGE_STEPS GENMASK(22, 16) +#define MARGINING_MAX_TIMING_OFFSET GENMASK(13, 8) +#define MARGINING_NUM_TIMING_STEPS GENMASK(5, 0) + +#define GEN4_LANE_MARGINING_2_OFF 0xB84 +#define MARGINING_IND_ERROR_SAMPLER BIT(28) +#define MARGINING_SAMPLE_REPORTING_METHOD BIT(27) +#define MARGINING_IND_LEFT_RIGHT_TIMING BIT(26) +#define MARGINING_IND_UP_DOWN_VOLTAGE BIT(25) +#define MARGINING_VOLTAGE_SUPPORTED BIT(24) +#define MARGINING_MAXLANES GENMASK(20, 16) +#define MARGINING_SAMPLE_RATE_TIMING GENMASK(13, 8) +#define MARGINING_SAMPLE_RATE_VOLTAGE GENMASK(5, 0) /* * iATU Unroll-specific register definitions * From 4.80 core version the address translation will be made by unroll diff --git a/drivers/pci/controller/dwc/pcie-qcom-common.c b/drivers/pci/co= ntroller/dwc/pcie-qcom-common.c index 596a35449de1..3aad19b56da8 100644 --- a/drivers/pci/controller/dwc/pcie-qcom-common.c +++ b/drivers/pci/controller/dwc/pcie-qcom-common.c @@ -45,3 +45,34 @@ void qcom_pcie_common_set_16gt_equalization(struct dw_pc= ie *pci) dw_pcie_writel_dbi(pci, GEN3_EQ_CONTROL_OFF, reg); } EXPORT_SYMBOL_GPL(qcom_pcie_common_set_16gt_equalization); + +void qcom_pcie_common_set_16gt_lane_margining(struct dw_pcie *pci) +{ + u32 reg; + + reg =3D dw_pcie_readl_dbi(pci, GEN4_LANE_MARGINING_1_OFF); + reg &=3D ~(MARGINING_MAX_VOLTAGE_OFFSET | + MARGINING_NUM_VOLTAGE_STEPS | + MARGINING_MAX_TIMING_OFFSET | + MARGINING_NUM_TIMING_STEPS); + reg |=3D FIELD_PREP(MARGINING_MAX_VOLTAGE_OFFSET, 0x24) | + FIELD_PREP(MARGINING_NUM_VOLTAGE_STEPS, 0x78) | + FIELD_PREP(MARGINING_MAX_TIMING_OFFSET, 0x32) | + FIELD_PREP(MARGINING_NUM_TIMING_STEPS, 0x10); + dw_pcie_writel_dbi(pci, GEN4_LANE_MARGINING_1_OFF, reg); + + reg =3D dw_pcie_readl_dbi(pci, GEN4_LANE_MARGINING_2_OFF); + reg |=3D MARGINING_IND_ERROR_SAMPLER | + MARGINING_SAMPLE_REPORTING_METHOD | + MARGINING_IND_LEFT_RIGHT_TIMING | + MARGINING_VOLTAGE_SUPPORTED; + reg &=3D ~(MARGINING_IND_UP_DOWN_VOLTAGE | + MARGINING_MAXLANES | + MARGINING_SAMPLE_RATE_TIMING | + MARGINING_SAMPLE_RATE_VOLTAGE); + reg |=3D FIELD_PREP(MARGINING_MAXLANES, pci->num_lanes) | + FIELD_PREP(MARGINING_SAMPLE_RATE_TIMING, 0x3f) | + FIELD_PREP(MARGINING_SAMPLE_RATE_VOLTAGE, 0x3f); + dw_pcie_writel_dbi(pci, GEN4_LANE_MARGINING_2_OFF, reg); +} +EXPORT_SYMBOL_GPL(qcom_pcie_common_set_16gt_lane_margining); diff --git a/drivers/pci/controller/dwc/pcie-qcom-common.h b/drivers/pci/co= ntroller/dwc/pcie-qcom-common.h index 536387e02e29..7d88d29e4766 100644 --- a/drivers/pci/controller/dwc/pcie-qcom-common.h +++ b/drivers/pci/controller/dwc/pcie-qcom-common.h @@ -9,5 +9,6 @@ struct dw_pcie; =20 void qcom_pcie_common_set_16gt_equalization(struct dw_pcie *pci); +void qcom_pcie_common_set_16gt_lane_margining(struct dw_pcie *pci); =20 #endif diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/contro= ller/dwc/pcie-qcom-ep.c index b091432d9f90..0df84e3e481c 100644 --- a/drivers/pci/controller/dwc/pcie-qcom-ep.c +++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c @@ -487,8 +487,10 @@ static int qcom_pcie_perst_deassert(struct dw_pcie *pc= i) goto err_disable_resources; } =20 - if (pcie_link_speed[pci->max_link_speed] =3D=3D PCIE_SPEED_16_0GT) + if (pcie_link_speed[pci->max_link_speed] =3D=3D PCIE_SPEED_16_0GT) { qcom_pcie_common_set_16gt_equalization(pci); + qcom_pcie_common_set_16gt_lane_margining(pci); + } =20 /* * The physical address of the MMIO region which is exposed as the BAR diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controlle= r/dwc/pcie-qcom.c index 6f7957c4adcc..068aa559ebd8 100644 --- a/drivers/pci/controller/dwc/pcie-qcom.c +++ b/drivers/pci/controller/dwc/pcie-qcom.c @@ -284,8 +284,10 @@ static int qcom_pcie_start_link(struct dw_pcie *pci) { struct qcom_pcie *pcie =3D to_qcom_pcie(pci); =20 - if (pcie_link_speed[pci->max_link_speed] =3D=3D PCIE_SPEED_16_0GT) + if (pcie_link_speed[pci->max_link_speed] =3D=3D PCIE_SPEED_16_0GT) { qcom_pcie_common_set_16gt_equalization(pci); + qcom_pcie_common_set_16gt_lane_margining(pci); + } =20 /* Enable Link Training state machine */ if (pcie->cfg->ops->ltssm_enable) --=20 2.25.1