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| author | Ethan Tidmore <ethantidmore06@gmail.com> | 2026-03-06 21:32:45 -0600 |
|---|---|---|
| committer | Luca Ceresoli <luca.ceresoli@bootlin.com> | 2026-03-17 18:04:08 +0100 |
| commit | a469749640fbcd2f49ab05fb83cca3da07f35ee3 (patch) | |
| tree | f932c0b9221eacdd180baa9c6e62fea0b575259a | |
| parent | 27a39e135f5c1ceaf73e64648eccdb42b751d5c7 (diff) | |
| download | linux-a469749640fbcd2f49ab05fb83cca3da07f35ee3.tar.gz linux-a469749640fbcd2f49ab05fb83cca3da07f35ee3.zip | |
drm/bridge: waveshare-dsi: Fix signedness bug
The function drm_of_get_data_lanes_count_ep() returns negative error
codes and dsi->lanes is an unsigned integer, so the check (dsi->lanes <
0) is always impossible.
Make the return value of drm_of_get_data_lanes_count_ep() be assigned to
ret, check for error, and then assign dsi->lanes to ret.
Detected by Smatch:
drivers/gpu/drm/bridge/waveshare-dsi.c:70 ws_bridge_attach_dsi() warn:
unsigned 'dsi->lanes' is never less than zero.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202603060341.hNj0pl9L-lkp@intel.com/
Fixes: fca11428425e9 ("drm/bridge: waveshare-dsi: Add support for 1..4 DSI data lanes")
Signed-off-by: Ethan Tidmore <ethantidmore06@gmail.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Link: https://patch.msgid.link/20260307033245.71666-1-ethantidmore06@gmail.com
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
| -rw-r--r-- | drivers/gpu/drm/bridge/waveshare-dsi.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/gpu/drm/bridge/waveshare-dsi.c b/drivers/gpu/drm/bridge/waveshare-dsi.c index 0497c7ecbc7a..32d40414adb9 100644 --- a/drivers/gpu/drm/bridge/waveshare-dsi.c +++ b/drivers/gpu/drm/bridge/waveshare-dsi.c @@ -66,11 +66,13 @@ static int ws_bridge_attach_dsi(struct ws_bridge *ws) dsi->mode_flags = MIPI_DSI_MODE_VIDEO_HSE | MIPI_DSI_MODE_VIDEO | MIPI_DSI_CLOCK_NON_CONTINUOUS; dsi->format = MIPI_DSI_FMT_RGB888; - dsi->lanes = drm_of_get_data_lanes_count_ep(dev->of_node, 0, 0, 1, 4); - if (dsi->lanes < 0) { + ret = drm_of_get_data_lanes_count_ep(dev->of_node, 0, 0, 1, 4); + if (ret < 0) { dev_warn(dev, "Invalid or missing DSI lane count %d, falling back to 2 lanes\n", - dsi->lanes); + ret); dsi->lanes = 2; /* Old DT backward compatibility */ + } else { + dsi->lanes = ret; } ret = devm_mipi_dsi_attach(dev, dsi); |