pci: Limit VPD length for megaraid_sas adapter
Reading or Writing of PCI VPD data causes system panic.
We saw this problem by running "lspci -vvv" in the beginning.
However this can be easily reproduced by running
cat /sys/bus/devices/XX../vpd
VPD length has been set as 32768 by default. Accessing vpd
will trigger read/write of 32k. This causes problem as we
could read data beyond the VPD end tag. Behaviour is un-
predictable when this happens. I see some other adapter doing
similar quirks(commit
bffadffd43d4 ("PCI: fix VPD limit quirk
for Broadcom 5708S"))
I see there is an attempt to fix this right way.
https://patchwork.ozlabs.org/patch/534843/ or
https://lkml.org/lkml/2015/10/23/97
Tried to fix it this way, but problem is I dont see the proper
start/end TAGs(at least for this adapter) at all. The data is
mostly junk or zeros. This patch fixes the issue by setting the
vpd length to 0x80.
Signed-off-by: Babu Moger <babu.moger@oracle.com>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Orabug:
22104511
Changes since v2 -> v3
Changed the vpd length from 0 to 0x80 which leaves the
option open for someone to read first few bytes.
Changes since v1 -> v2
Removed the changes in pci_id.h. Kept all the vendor
ids in quirks.c