commit 0c551abfa0 upstream.
By default old pre-3.0 Freescale PCIe controllers reports invalid PCI Class
Code 0x0b20 for PCIe Root Port. It can be seen by lspci -b output on P2020
board which has this pre-3.0 controller:
$ lspci -bvnn
00:00.0 Power PC [0b20]: Freescale Semiconductor Inc P2020E [1957:0070] (rev 21)
!!! Invalid class 0b20 for header type 01
Capabilities: [4c] Express Root Port (Slot-), MSI 00
Fix this issue by programming correct PCI Class Code 0x0604 for PCIe Root
Port to the Freescale specific PCIe register 0x474.
With this change lspci -b output is:
$ lspci -bvnn
00:00.0 PCI bridge [0604]: Freescale Semiconductor Inc P2020E [1957:0070] (rev 21) (prog-if 00 [Normal decode])
Capabilities: [4c] Express Root Port (Slot-), MSI 00
Without any "Invalid class" error. So class code was properly reflected
into standard (read-only) PCI register 0x08.
Same fix is already implemented in U-Boot pcie_fsl.c driver in commit:
d18d06ac35
Fix activated by U-Boot stay active also after booting Linux kernel.
But boards which use older U-Boot version without that fix are affected and
still require this fix.
So implement this class code fix also in kernel fsl_pci.c driver.
Cc: stable@vger.kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220706101043.4867-1-pali@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
b80b14c6c0