From: Neil Armstrong <neil.armstrong@linaro.org>
To: "Manivannan Sadhasivam" <manivannan.sadhasivam@oss.qualcomm.com>,
"Bjorn Helgaas" <bhelgaas@google.com>,
"Lorenzo Pieralisi" <lpieralisi@kernel.org>,
"Krzysztof Wilczyński" <kwilczynski@kernel.org>,
"Manivannan Sadhasivam" <mani@kernel.org>,
"Rob Herring" <robh@kernel.org>,
"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
"Conor Dooley" <conor+dt@kernel.org>,
"Hanjie Lin" <hanjie.lin@amlogic.com>,
"Yue Wang" <yue.wang@amlogic.com>,
"Kevin Hilman" <khilman@baylibre.com>,
"Jerome Brunet" <jbrunet@baylibre.com>,
"Martin Blumenstingl" <martin.blumenstingl@googlemail.com>,
"Andrew Murray" <amurray@thegoodpenguin.co.uk>,
"Jingoo Han" <jingoohan1@gmail.com>,
"Krishna Chaitanya Chundru" <krishna.chundru@oss.qualcomm.com>
Cc: linux-pci@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-amlogic@lists.infradead.org, stable@vger.kernel.org,
Linnaea Lavia <linnaea-von-lavia@live.com>
Subject: Re: [PATCH RESEND 3/3] PCI: meson: Fix parsing the DBI register region
Date: Thu, 6 Nov 2025 11:00:29 +0100 [thread overview]
Message-ID: <1c31a5ef-39f6-460b-8046-3c7b2627e3ba@linaro.org> (raw)
In-Reply-To: <20251101-pci-meson-fix-v1-3-c50dcc56ed6a@oss.qualcomm.com>
Hi,
On 11/1/25 05:29, Manivannan Sadhasivam wrote:
> First of all, the driver was parsing the 'dbi' register region as 'elbi'.
> This was due to DT mistakenly passing 'dbi' as 'elbi'. Since the DT is
> now fixed to supply 'dbi' region, this driver can rely on the DWC core
> driver to parse and map it.
>
> However, to support the old DTs, if the 'elbi' region is found in DT, parse
> and map the region as both 'dw_pcie::elbi_base' as 'dw_pcie::dbi_base'.
> This will allow the driver to work with both broken and fixed DTs.
>
> Also, skip parsing the 'elbi' region in DWC core if 'pci->elbi_base' was
> already populated.
>
> Cc: <stable@vger.kernel.org> # 6.2
> Reported-by: Linnaea Lavia <linnaea-von-lavia@live.com>
> Closes: https://lore.kernel.org/linux-pci/DM4PR05MB102707B8CDF84D776C39F22F2C7F0A@DM4PR05MB10270.namprd05.prod.outlook.com/
> Fixes: 9c0ef6d34fdb ("PCI: amlogic: Add the Amlogic Meson PCIe controller driver")
> Fixes: c96992a24bec ("PCI: dwc: Add support for ELBI resource mapping")
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
> ---
> drivers/pci/controller/dwc/pci-meson.c | 18 +++++++++++++++---
> drivers/pci/controller/dwc/pcie-designware.c | 12 +++++++-----
> 2 files changed, 22 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pci-meson.c b/drivers/pci/controller/dwc/pci-meson.c
> index 787469d1b396d4c7b3e28edfe276b7b997fb8aee..54b6a4196f1767a3c14c6c901bfee3505588134c 100644
> --- a/drivers/pci/controller/dwc/pci-meson.c
> +++ b/drivers/pci/controller/dwc/pci-meson.c
> @@ -108,10 +108,22 @@ static int meson_pcie_get_mems(struct platform_device *pdev,
> struct meson_pcie *mp)
> {
> struct dw_pcie *pci = &mp->pci;
> + struct resource *res;
>
> - pci->dbi_base = devm_platform_ioremap_resource_byname(pdev, "elbi");
> - if (IS_ERR(pci->dbi_base))
> - return PTR_ERR(pci->dbi_base);
> + /*
> + * For the broken DTs that supply 'dbi' as 'elbi', parse the 'elbi'
> + * region and assign it to both 'pci->elbi_base' and 'pci->dbi_space' so
> + * that the DWC core can skip parsing both regions.
> + */
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "elbi");
> + if (res) {
> + pci->elbi_base = devm_pci_remap_cfg_resource(pci->dev, res);
> + if (IS_ERR(pci->elbi_base))
> + return PTR_ERR(pci->elbi_base);
> +
> + pci->dbi_base = pci->elbi_base;
> + pci->dbi_phys_addr = res->start;
> + }
>
> mp->cfg_base = devm_platform_ioremap_resource_byname(pdev, "cfg");
> if (IS_ERR(mp->cfg_base))
> diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
> index c644216995f69cbf065e61a0392bf1e5e32cf56e..06eca858eb1b3c7a8a833df6616febcdbe854850 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.c
> +++ b/drivers/pci/controller/dwc/pcie-designware.c
> @@ -168,11 +168,13 @@ int dw_pcie_get_resources(struct dw_pcie *pci)
> }
>
> /* ELBI is an optional resource */
> - res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "elbi");
> - if (res) {
> - pci->elbi_base = devm_ioremap_resource(pci->dev, res);
> - if (IS_ERR(pci->elbi_base))
> - return PTR_ERR(pci->elbi_base);
> + if (!pci->elbi_base) {
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "elbi");
> + if (res) {
> + pci->elbi_base = devm_ioremap_resource(pci->dev, res);
> + if (IS_ERR(pci->elbi_base))
> + return PTR_ERR(pci->elbi_base);
> + }
> }
>
> /* LLDD is supposed to manually switch the clocks and resets state */
>
Tested with "old" and "new" DT worked fine with both:
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on Bananapi-M2S
Thanks,
Neil
next prev parent reply other threads:[~2025-11-06 10:00 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-01 4:29 [PATCH RESEND 0/3] PCI: meson: Fix the parsing of DBI region Manivannan Sadhasivam
2025-11-01 4:29 ` [PATCH RESEND 1/3] dt-bindings: PCI: amlogic: Fix the register name of the " Manivannan Sadhasivam
2025-11-03 9:47 ` Neil Armstrong
2025-11-03 10:12 ` Manivannan Sadhasivam
2025-11-06 8:30 ` Krzysztof Kozlowski
2025-11-06 9:06 ` Manivannan Sadhasivam
2025-11-08 10:40 ` Manivannan Sadhasivam
2025-11-10 6:40 ` Neil Armstrong
2025-11-01 4:29 ` [PATCH RESEND 2/3] arm64: dts: amlogic: Fix the register name of the 'DBI' region Manivannan Sadhasivam
2025-11-03 9:47 ` Neil Armstrong
2025-11-01 4:29 ` [PATCH RESEND 3/3] PCI: meson: Fix parsing the DBI register region Manivannan Sadhasivam
2025-11-03 9:49 ` Neil Armstrong
2025-11-06 10:00 ` Neil Armstrong [this message]
2025-11-03 9:50 ` [PATCH RESEND 0/3] PCI: meson: Fix the parsing of DBI region Neil Armstrong
2025-11-03 10:14 ` Manivannan Sadhasivam
2025-11-10 6:56 ` (subset) " Manivannan Sadhasivam
2025-11-10 8:18 ` Neil Armstrong
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