| Message ID | 20210827121444.7628-1-pali@kernel.org |
|---|---|
| State | Accepted |
| Commit | 758262bc266aa65cfbfd74033c3ac1e4e67c92ec |
| Delegated to: | Stefan Roese |
| Headers | show |
| Series | [1/2] arm: a37xx: pci: Disable returning CRS response | expand |
On 27.08.21 14:14, Pali Rohár wrote: > There was mistake in commit 4cd61c43fd51 ("arm: a37xx: pci: Fix handling > PIO config error responses"). U-Boot does not support handling of CRS > return value for PCI_VENDOR_ID config read request and also does not set > CRSSVE bit. > > Therefore disable returning CRS response for now. > > Signed-off-by: Pali Rohár <pali@kernel.org> > Fixes: 4cd61c43fd51 ("arm: a37xx: pci: Fix handling PIO config error responses") Reviewed-by: Stefan Roese <sr@denx.de> Thanks, Stefan > --- > drivers/pci/pci-aardvark.c | 13 ++++++++++++- > 1 file changed, 12 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/pci-aardvark.c b/drivers/pci/pci-aardvark.c > index 815b26162f15..d3ef8f203d97 100644 > --- a/drivers/pci/pci-aardvark.c > +++ b/drivers/pci/pci-aardvark.c > @@ -358,7 +358,18 @@ static int pcie_advk_read_config(const struct udevice *bus, pci_dev_t bdf, > return 0; > } > > - allow_crs = (offset == PCI_VENDOR_ID) && (size == 4); > + /* > + * Returning fabricated CRS value (0xFFFF0001) by PCIe Root Complex to > + * OS is allowed only for 4-byte PCI_VENDOR_ID config read request and > + * only when CRSSVE bit in Root Port PCIe device is enabled. In all > + * other error PCIe Root Complex must return all-ones. > + * Aardvark HW does not have Root Port PCIe device and U-Boot does not > + * implement emulation of this device. > + * U-Boot currently does not support handling of CRS return value for > + * PCI_VENDOR_ID config read request and also does not set CRSSVE bit. > + * Therefore disable returning CRS response for now. > + */ > + allow_crs = false; > > if (advk_readl(pcie, PIO_START)) { > dev_err(pcie->dev, > Viele Grüße, Stefan
diff --git a/drivers/pci/pci-aardvark.c b/drivers/pci/pci-aardvark.c index 815b26162f15..d3ef8f203d97 100644 --- a/drivers/pci/pci-aardvark.c +++ b/drivers/pci/pci-aardvark.c @@ -358,7 +358,18 @@ static int pcie_advk_read_config(const struct udevice *bus, pci_dev_t bdf, return 0; } - allow_crs = (offset == PCI_VENDOR_ID) && (size == 4); + /* + * Returning fabricated CRS value (0xFFFF0001) by PCIe Root Complex to + * OS is allowed only for 4-byte PCI_VENDOR_ID config read request and + * only when CRSSVE bit in Root Port PCIe device is enabled. In all + * other error PCIe Root Complex must return all-ones. + * Aardvark HW does not have Root Port PCIe device and U-Boot does not + * implement emulation of this device. + * U-Boot currently does not support handling of CRS return value for + * PCI_VENDOR_ID config read request and also does not set CRSSVE bit. + * Therefore disable returning CRS response for now. + */ + allow_crs = false; if (advk_readl(pcie, PIO_START)) { dev_err(pcie->dev,
There was mistake in commit 4cd61c43fd51 ("arm: a37xx: pci: Fix handling PIO config error responses"). U-Boot does not support handling of CRS return value for PCI_VENDOR_ID config read request and also does not set CRSSVE bit. Therefore disable returning CRS response for now. Signed-off-by: Pali Rohár <pali@kernel.org> Fixes: 4cd61c43fd51 ("arm: a37xx: pci: Fix handling PIO config error responses") --- drivers/pci/pci-aardvark.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)