Re: [PATCH v6 2/2] drm/bridge: Add NWL MIPI DSI host controller support

From: kbuild test robot
Date: Sun Sep 22 2019 - 18:56:15 EST


Hi "Guido,

I love your patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[cannot apply to v5.3 next-20190920]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url: https://github.com/0day-ci/linux/commits/Guido-G-nther/drm-bridge-Add-NWL-MIPI-DSI-host-controller-support/20190923-005010

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@xxxxxxxxx>

smatch warnings:
drivers/gpu/drm/bridge/nwl-dsi.c:272 nwl_dsi_config_dpi() warn: unsigned 'color_format' is never less than zero.

vim +/color_format +272 drivers/gpu/drm/bridge/nwl-dsi.c

245
246 static int nwl_dsi_config_dpi(struct nwl_dsi *dsi)
247 {
248 u32 color_format, mode;
249 bool burst_mode;
250 int hfront_porch, hback_porch, vfront_porch, vback_porch;
251 int hsync_len, vsync_len;
252
253 hfront_porch = dsi->mode.hsync_start - dsi->mode.hdisplay;
254 hsync_len = dsi->mode.hsync_end - dsi->mode.hsync_start;
255 hback_porch = dsi->mode.htotal - dsi->mode.hsync_end;
256
257 vfront_porch = dsi->mode.vsync_start - dsi->mode.vdisplay;
258 vsync_len = dsi->mode.vsync_end - dsi->mode.vsync_start;
259 vback_porch = dsi->mode.vtotal - dsi->mode.vsync_end;
260
261 DRM_DEV_DEBUG_DRIVER(dsi->dev, "hfront_porch = %d\n", hfront_porch);
262 DRM_DEV_DEBUG_DRIVER(dsi->dev, "hback_porch = %d\n", hback_porch);
263 DRM_DEV_DEBUG_DRIVER(dsi->dev, "hsync_len = %d\n", hsync_len);
264 DRM_DEV_DEBUG_DRIVER(dsi->dev, "hdisplay = %d\n", dsi->mode.hdisplay);
265 DRM_DEV_DEBUG_DRIVER(dsi->dev, "vfront_porch = %d\n", vfront_porch);
266 DRM_DEV_DEBUG_DRIVER(dsi->dev, "vback_porch = %d\n", vback_porch);
267 DRM_DEV_DEBUG_DRIVER(dsi->dev, "vsync_len = %d\n", vsync_len);
268 DRM_DEV_DEBUG_DRIVER(dsi->dev, "vactive = %d\n", dsi->mode.vdisplay);
269 DRM_DEV_DEBUG_DRIVER(dsi->dev, "clock = %d kHz\n", dsi->mode.clock);
270
271 color_format = nwl_dsi_get_dpi_pixel_format(dsi->format);
> 272 if (color_format < 0) {
273 DRM_DEV_ERROR(dsi->dev, "Invalid color format 0x%x\n",
274 dsi->format);
275 return color_format;
276 }
277 DRM_DEV_DEBUG_DRIVER(dsi->dev, "pixel fmt = %d\n", dsi->format);
278
279 nwl_dsi_write(dsi, NWL_DSI_INTERFACE_COLOR_CODING, NWL_DSI_DPI_24_BIT);
280 nwl_dsi_write(dsi, NWL_DSI_PIXEL_FORMAT, color_format);
281 /*
282 * Adjusting input polarity based on the video mode results in
283 * a black screen so always pick active low:
284 */
285 nwl_dsi_write(dsi, NWL_DSI_VSYNC_POLARITY,
286 NWL_DSI_VSYNC_POLARITY_ACTIVE_LOW);
287 nwl_dsi_write(dsi, NWL_DSI_HSYNC_POLARITY,
288 NWL_DSI_HSYNC_POLARITY_ACTIVE_LOW);
289
290 burst_mode = (dsi->dsi_mode_flags & MIPI_DSI_MODE_VIDEO_BURST) &&
291 !(dsi->dsi_mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE);
292
293 if (burst_mode) {
294 nwl_dsi_write(dsi, NWL_DSI_VIDEO_MODE, NWL_DSI_VM_BURST_MODE);
295 nwl_dsi_write(dsi, NWL_DSI_PIXEL_FIFO_SEND_LEVEL, 256);
296 } else {
297 mode = ((dsi->dsi_mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) ?
298 NWL_DSI_VM_BURST_MODE_WITH_SYNC_PULSES :
299 NWL_DSI_VM_NON_BURST_MODE_WITH_SYNC_EVENTS);
300 nwl_dsi_write(dsi, NWL_DSI_VIDEO_MODE, mode);
301 nwl_dsi_write(dsi, NWL_DSI_PIXEL_FIFO_SEND_LEVEL,
302 dsi->mode.hdisplay);
303 }
304
305 nwl_dsi_write(dsi, NWL_DSI_HFP, hfront_porch);
306 nwl_dsi_write(dsi, NWL_DSI_HBP, hback_porch);
307 nwl_dsi_write(dsi, NWL_DSI_HSA, hsync_len);
308
309 nwl_dsi_write(dsi, NWL_DSI_ENABLE_MULT_PKTS, 0x0);
310 nwl_dsi_write(dsi, NWL_DSI_BLLP_MODE, 0x1);
311 nwl_dsi_write(dsi, NWL_DSI_USE_NULL_PKT_BLLP, 0x0);
312 nwl_dsi_write(dsi, NWL_DSI_VC, 0x0);
313
314 nwl_dsi_write(dsi, NWL_DSI_PIXEL_PAYLOAD_SIZE, dsi->mode.hdisplay);
315 nwl_dsi_write(dsi, NWL_DSI_VACTIVE, dsi->mode.vdisplay - 1);
316 nwl_dsi_write(dsi, NWL_DSI_VBP, vback_porch);
317 nwl_dsi_write(dsi, NWL_DSI_VFP, vfront_porch);
318
319 return 0;
320 }
321

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