[ Upstream commit 5459c0b7046752e519a646e1c2404852bb628459 ]
Some Root Ports on Intel Tiger Lake and Alder Lake systems support the RP
Extensions for DPC and the RP PIO Log registers but incorrectly advertise
an RP PIO Log Size of zero. This means the kernel complains that:
DPC: RP PIO log size 0 is invalid
and if DPC is triggered, the DPC driver will not dump the RP PIO Log
registers when it should.
This is caused by a BIOS bug and should be fixed the BIOS for future CPUs.
Add a quirk to set the correct RP PIO Log size for the affected Root Ports.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=209943
Link: https://lore.kernel.org/r/20220816102042.69125-1-mika.westerberg@linux.intel.com
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Stable-dep-of: 627c6db20703 ("PCI/DPC: Quirk PIO log size for Intel Raptor Lake Root Ports")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6568d82512b0a64809acff3d7a747362fa4288c8 ]
The TLP Prefix Log Register consists of multiple DWORDs (PCIe r6.1 sec
7.9.14.13) but the loop in dpc_process_rp_pio_error() keeps reading from
the first DWORD, so we print only the first PIO TLP Prefix (duplicated
several times), and we never print the second, third, etc., Prefixes.
Add the iteration count based offset calculation into the config read.
Fixes: f20c4ea49ec4 ("PCI/DPC: Add eDPC support")
Link: https://lore.kernel.org/r/20240118110815.3867-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
[bhelgaas: add user-visible details to commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
