[PATCH 5.14 845/849] PCI: aardvark: Fix PCIe Max Payload Size setting

Greg Kroah-Hartman
2021-11-16T01:16:09Z

From: Pali Rohár <pali@kernel.org>

commit a4e17d65dafdd3513042d8f00404c9b6068a825c upstream.

Change PCIe Max Payload Size setting in PCIe Device Control register to 512
bytes to align with PCIe Link Initialization sequence as defined in Marvell
Armada 3700 Functional Specification. According to the specification,
maximal Max Payload Size supported by this device is 512 bytes.

Without this kernel prints suspicious line:

pci 0000:01:00.0: Upstream bridge's Max Payload Size set to 256 (was 16384, max 512)

With this change it changes to:

pci 0000:01:00.0: Upstream bridge's Max Payload Size set to 256 (was 512, max 512)

Link: https://lore.kernel.org/r/20211005180952.6812-3-kabel@kernel.org
Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/pci/controller/pci-aardvark.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -597,8 +597,9 @@ static void advk_pcie_setup_hw(struct ad
reg = advk_readl(pcie, PCIE_CORE_PCIEXP_CAP + PCI_EXP_DEVCTL);
reg &= ~PCI_EXP_DEVCTL_RELAX_EN;
reg &= ~PCI_EXP_DEVCTL_NOSNOOP_EN;
+ reg &= ~PCI_EXP_DEVCTL_PAYLOAD;
reg &= ~PCI_EXP_DEVCTL_READRQ;
- reg |= PCI_EXP_DEVCTL_PAYLOAD; /* Set max payload size */
+ reg |= PCI_EXP_DEVCTL_PAYLOAD_512B;
reg |= PCI_EXP_DEVCTL_READRQ_512B;
advk_writel(pcie, reg, PCIE_CORE_PCIEXP_CAP + PCI_EXP_DEVCTL);