[PATCH v4 16/18] fpga: of-fpga-region: accept overlays that don't program FPGA

From: Alan Tull
Date: Wed Sep 13 2017 - 16:49:23 EST


The FPGA may already have a static image programmed when
Linux boots. In that case a DT overlay may be used to add
the devices that already exist. This commit allows that
by shuffling the order of some checks.

Signed-off-by: Alan Tull <atull@xxxxxxxxxx>
---
v4: Patch added to patchset in v4
---
drivers/fpga/of-fpga-region.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/fpga/of-fpga-region.c b/drivers/fpga/of-fpga-region.c
index 1797057..d942ae1 100644
--- a/drivers/fpga/of-fpga-region.c
+++ b/drivers/fpga/of-fpga-region.c
@@ -298,18 +298,19 @@ static int of_fpga_region_notify_pre_apply(struct fpga_region *region,
struct fpga_image_info *info;
int ret;

- if (region->info) {
- dev_err(dev, "Region already has overlay applied.\n");
- return -EINVAL;
- }
-
info = of_fpga_region_parse_ov(region, nd->overlay);
if (IS_ERR(info))
return PTR_ERR(info);

+ /* If overlay doesn't program the FPGA, accept it anyway. */
if (!info)
return 0;

+ if (region->info) {
+ dev_err(dev, "Region already has overlay applied.\n");
+ return -EINVAL;
+ }
+
region->info = info;
ret = fpga_region_program_fpga(region);
if (ret) {
--
2.7.4