From: Bjorn Helgaas <helgaas@kernel.org>
To: Ziyue Zhang <ziyue.zhang@oss.qualcomm.com>
Cc: andersson@kernel.org, konradybcio@kernel.org, robh@kernel.org,
krzk+dt@kernel.org, conor+dt@kernel.org, jingoohan1@gmail.com,
mani@kernel.org, lpieralisi@kernel.org, kwilczynski@kernel.org,
bhelgaas@google.com, johan+linaro@kernel.org, vkoul@kernel.org,
kishon@kernel.org, neil.armstrong@linaro.org,
abel.vesa@linaro.org, kw@linux.com,
linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
linux-phy@lists.infradead.org, qiang.yu@oss.qualcomm.com,
quic_krichai@quicinc.com, quic_vbadigan@quicinc.com
Subject: Re: [PATCH v6 1/3] PCI: qcom: Add equalization settings for 8.0 GT/s and 32.0 GT/s
Date: Thu, 4 Sep 2025 11:14:48 -0500 [thread overview]
Message-ID: <20250904161448.GA1265317@bhelgaas> (raw)
In-Reply-To: <20250904065225.1762793-2-ziyue.zhang@oss.qualcomm.com>
On Thu, Sep 04, 2025 at 02:52:23PM +0800, Ziyue Zhang wrote:
> Add lane equalization setting for 8.0 GT/s and 32.0 GT/s to enhance link
> stability and avoid AER Correctable Errors reported on some platforms
> (eg. SA8775P).
>
> 8.0 GT/s, 16.0 GT/s and 32.0 GT/s require the same equalization setting.
> This setting is programmed into a group of shadow registers, which can be
> switched to configure equalization for different speeds by writing 00b,
> 01b and 10b to `RATE_SHADOW_SEL`.
>
> Hence program equalization registers in a loop using link speed as index,
> so that equalization setting can be programmed for 8.0 GT/s, 16.0 GT/s
> and 32.0 GT/s.
>
> Fixes: 489f14be0e0a ("arm64: dts: qcom: sa8775p: Add pcie0 and pcie1 nodes")
>
Drop this blank line.
> Co-developed-by: Qiang Yu <qiang.yu@oss.qualcomm.com>
> Signed-off-by: Qiang Yu <qiang.yu@oss.qualcomm.com>
> Signed-off-by: Ziyue Zhang <ziyue.zhang@oss.qualcomm.com>
> +++ b/drivers/pci/controller/dwc/pcie-qcom-common.c
> + for (speed = PCIE_SPEED_8_0GT; speed <= pcie_link_speed[pci->max_link_speed]; ++speed) {
Use "speed++" when there's no need for preincrement to follow typical
drivers/pci/ usage.
No need to repost for these.
next prev parent reply other threads:[~2025-09-04 16:14 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-04 6:52 [PATCH v6 0/3] Add Equalization Settings for 8.0 GT/s and 32.0 GT/s and Add PCIe Lane Equalization Preset Properties for 8.0 GT/s and 16.0 GT/s Ziyue Zhang
2025-09-04 6:52 ` [PATCH v6 1/3] PCI: qcom: Add equalization settings for 8.0 GT/s and 32.0 GT/s Ziyue Zhang
2025-09-04 16:14 ` Bjorn Helgaas [this message]
2025-09-04 6:52 ` [PATCH v6 2/3] PCI: qcom: fix macro typo for CURSOR Ziyue Zhang
2025-09-04 16:17 ` Bjorn Helgaas
2025-09-04 6:52 ` [PATCH v6 3/3] arm64: dts: qcom: lemans: Add PCIe lane equalization preset properties Ziyue Zhang
2025-09-04 16:56 ` (subset) [PATCH v6 0/3] Add Equalization Settings for 8.0 GT/s and 32.0 GT/s and Add PCIe Lane Equalization Preset Properties for 8.0 GT/s and 16.0 GT/s Manivannan Sadhasivam
2025-09-17 0:45 ` Bjorn Andersson
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