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.

As 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 will start to happen when the driver is reused for a 32-bit SoC (e.g. i.MX7ULP), or when code is copied for a new driver.

Signed-off-by: Geert Uytterhoeven geert+renesas@glider.be Reviewed-by: Fabio Estevam festevam@gmail.com Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com --- Compile-tested only.

v2: - Add Reviewed-by, - Add reference to i.MX7ULP. --- 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 873995f0a7416e58..6002404ffcb9df08 100644 --- a/drivers/gpu/drm/bridge/nwl-dsi.c +++ b/drivers/gpu/drm/bridge/nwl-dsi.c @@ -196,7 +196,7 @@ 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); }

/*