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From: sashiko-bot@kernel.org
To: "Bjorn Helgaas" <helgaas@kernel.org>
Cc: linux-pci@vger.kernel.org
Subject: Re: [PATCH v2] PCI: tegra264: Fix Link Capabilities register offset
Date: Wed, 23 Sep 2026 20:03:47 +0000	[thread overview]
Message-ID: <20260923200347.7BBFB1F000FF@smtp.kernel.org> (raw)
In-Reply-To: <20260923195719.1933175-2-bhelgaas@google.com>

> The PCI Express Capability begins at 0x48.  Link Capabilities is a 32-bit
> register at offset 0xc, and Link Status is a 16-bit register at offset
> 0x12:
> 
>   Link Capabilities is at 0x48 + 0xc  = 0x54
>   Link Status       is at 0x48 + 0x12 = 0x5a
> 
> Previously the driver read Link Capabilities with a 16-bit read from
> XTL_RC_PCIE_CFG_LINK_CAPS (0x56), which incorrectly read just the upper
> half of the register.  When a hotplug-capable port has no link during
> probe, tegra264_pcie_icc_set() consequently derives the maximum speed and
> width from unrelated bits and requests the wrong interconnect bandwidth.
> 
> Correct the Link Capabilities usage by adding a XTL_RC_PCIE_CAP definition
> for the base of the PCIe Capability, using the existing PCI_EXP_LNKCAP
> (0xc) and PCI_EXP_LNKSTA (0x12) offsets so they're easily searchable, and
> reading the entire 32 bits of Link Capabilities.
> 
> Fixes: 01c3c27a0ef6 ("PCI: tegra264: Add Tegra264 support")
> Based-on-patch-by: Linmao Li <lilinmao@kylinos.cn>
> Link: https://lore.kernel.org/20260827093919.2825467-1-lilinmao@kylinos.cn
> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260923195719.1933175-2-bhelgaas@google.com?part=1


  reply	other threads:[~2026-09-23 20:03 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-23 19:57 [PATCH v2] PCI: tegra264: Fix Link Capabilities register offset Bjorn Helgaas
2026-09-23 20:03 ` sashiko-bot [this message]
2026-09-30 19:46 ` Bjorn Helgaas
2026-10-01  7:40 ` Thierry Reding
2026-10-01 16:43   ` Bjorn Helgaas

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