As nwl_dsi.lanes is u32, and NSEC_PER_SEC is 1000000000L, the second
multiplication in
dsi->lanes * 8 * NSEC_PER_SEC
will overflow on a 32-bit platform. Fix this by making the constant
unsigned long long, forcing 64-bit arithmetic.
While iMX8 is arm64, this driver is currently used on 64-bit platforms
only, where long is 64-bit, so this cannot happen. But the issue may
start to happen when the driver is reused for a 32-bit SoC, or when code
is copied for a new driver.
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
Compile-tested only.
---
drivers/gpu/drm/bridge/nwl-dsi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/nwl-dsi.c b/drivers/gpu/drm/bridge/nwl-dsi.c
index 66b67402f1acd57d..a8da3081efdcc84e 100644
--- a/drivers/gpu/drm/bridge/nwl-dsi.c
+++ b/drivers/gpu/drm/bridge/nwl-dsi.c
@@ -195,7 +195,7 @@ static u32 ps2bc(struct nwl_dsi *dsi, unsigned long long ps)
u32 bpp = mipi_dsi_pixel_format_to_bpp(dsi->format);
return DIV64_U64_ROUND_UP(ps * dsi->mode.clock * bpp,
- dsi->lanes * 8 * NSEC_PER_SEC);
+ dsi->lanes * 8ULL * NSEC_PER_SEC);
}
/*
--
2.25.1
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