CSR address space for Accelerator Functional Units (AFU) is not available during the early Device Feature List (DFL) enumeration. Early access to this space results in invalid data and port errors. This change adds a condition to prevent an early read from the AFU CSR space.
Signed-off-by: Russ Weight russell.h.weight@intel.com
Fixes: 23bcda750558 ("fpga: dfl: expose feature revision from struct dfl_device") Cc: stable@vger.kernel.org --- drivers/fpga/dfl.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c index c99b78ee008a..f86666cf2c6a 100644 --- a/drivers/fpga/dfl.c +++ b/drivers/fpga/dfl.c @@ -1019,16 +1019,18 @@ create_feature_instance(struct build_feature_devs_info *binfo, { unsigned int irq_base, nr_irqs; struct dfl_feature_info *finfo; + u8 revision = 0; int ret; - u8 revision; u64 v;
- v = readq(binfo->ioaddr + ofst); - revision = FIELD_GET(DFH_REVISION, v); + if (fid != FEATURE_ID_AFU) { + v = readq(binfo->ioaddr + ofst); + revision = FIELD_GET(DFH_REVISION, v);
- /* read feature size and id if inputs are invalid */ - size = size ? size : feature_size(v); - fid = fid ? fid : feature_id(v); + /* read feature size and id if inputs are invalid */ + size = size ? size : feature_size(v); + fid = fid ? fid : feature_id(v); + }
if (binfo->len - ofst < size) return -EINVAL;