[Intel-gfx] [CI v12 10/23] drm/i915/dsc: Define & Compute VESA DSC params (fwd)
Julia Lawall
julia.lawall at lip6.fr
Wed Nov 28 18:50:38 UTC 2018
On Wed, 28 Nov 2018, Manasi Navare wrote:
> On Wed, Nov 28, 2018 at 11:46:26AM +0000, Julia Lawall wrote:
> > Hello,
> >
> > row_index and column_index are unsigned, so in the last line shown
> > they will not be less than 0.
> >
>
> Row_index and column_index are assigned to 0 at the beginning of the function and so
> if thre is no valid index found the get_column_index /row_index will return -EINVAL
> and hence they can have values < 0.
Since they have an unsigned type, the negative values will be considered
to be really big positive numbers.
julia
>
> Does this make sense?
>
> Manasi
>
> > julia
> >
> > ---------- Forwarded message ----------
> > Date: Wed, 28 Nov 2018 19:43:30 +0800
> > From: kbuild test robot <lkp at intel.com>
> > To: kbuild at 01.org
> > Cc: Julia Lawall <julia.lawall at lip6.fr>
> > Subject: Re: [Intel-gfx] [CI v12 10/23] drm/i915/dsc: Define & Compute VESA DSC
> > params
> >
> > CC: kbuild-all at 01.org
> > In-Reply-To: <20181127214125.17658-10-manasi.d.navare at intel.com>
> > References: <20181127214125.17658-10-manasi.d.navare at intel.com>
> > TO: Manasi Navare <manasi.d.navare at intel.com>
> > CC: intel-gfx at lists.freedesktop.org
> > CC:
> >
> > Hi Gaurav,
> >
> > Thank you for the patch! Perhaps something to improve:
> >
> > [auto build test WARNING on drm-intel/for-linux-next]
> > [also build test WARNING on next-20181127]
> > [cannot apply to v4.20-rc4]
> > [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
> >
> > url: https://github.com/0day-ci/linux/commits/Manasi-Navare/drm-dsc-Modify-DRM-helper-to-return-complete-DSC-color-depth-capabilities/20181128-095026
> > base: git://anongit.freedesktop.org/drm-intel for-linux-next
> > :::::: branch date: 10 hours ago
> > :::::: commit date: 10 hours ago
> >
> > >> drivers/gpu/drm/i915/intel_vdsc.c:404:22-34: WARNING: Unsigned expression compared with zero: column_index < 0
> > >> drivers/gpu/drm/i915/intel_vdsc.c:404:5-14: WARNING: Unsigned expression compared with zero: row_index < 0
> >
> > # https://github.com/0day-ci/linux/commit/5b6895999d5a84b154fcd49dc3a91d71897d03ec
> > git remote add linux-review https://github.com/0day-ci/linux
> > git remote update linux-review
> > git checkout 5b6895999d5a84b154fcd49dc3a91d71897d03ec
> > vim +404 drivers/gpu/drm/i915/intel_vdsc.c
> >
> > 5b689599 Gaurav K Singh 2018-11-27 319
> > 5b689599 Gaurav K Singh 2018-11-27 320 int intel_dp_compute_dsc_params(struct intel_dp *intel_dp,
> > 5b689599 Gaurav K Singh 2018-11-27 321 struct intel_crtc_state *pipe_config)
> > 5b689599 Gaurav K Singh 2018-11-27 322 {
> > 5b689599 Gaurav K Singh 2018-11-27 323 struct drm_dsc_config *vdsc_cfg = &pipe_config->dp_dsc_cfg;
> > 5b689599 Gaurav K Singh 2018-11-27 324 u16 compressed_bpp = pipe_config->dsc_params.compressed_bpp;
> > 5b689599 Gaurav K Singh 2018-11-27 325 u8 i = 0;
> > 5b689599 Gaurav K Singh 2018-11-27 326 u8 row_index = 0;
> > 5b689599 Gaurav K Singh 2018-11-27 327 u8 column_index = 0;
> > 5b689599 Gaurav K Singh 2018-11-27 328 u8 line_buf_depth = 0;
> > 5b689599 Gaurav K Singh 2018-11-27 329
> > 5b689599 Gaurav K Singh 2018-11-27 330 vdsc_cfg->pic_width = pipe_config->base.adjusted_mode.crtc_hdisplay;
> > 5b689599 Gaurav K Singh 2018-11-27 331 vdsc_cfg->pic_height = pipe_config->base.adjusted_mode.crtc_vdisplay;
> > 5b689599 Gaurav K Singh 2018-11-27 332 vdsc_cfg->slice_width = DIV_ROUND_UP(vdsc_cfg->pic_width,
> > 5b689599 Gaurav K Singh 2018-11-27 333 pipe_config->dsc_params.slice_count);
> > 5b689599 Gaurav K Singh 2018-11-27 334 /*
> > 5b689599 Gaurav K Singh 2018-11-27 335 * Slice Height of 8 works for all currently available panels. So start
> > 5b689599 Gaurav K Singh 2018-11-27 336 * with that if pic_height is an integral multiple of 8.
> > 5b689599 Gaurav K Singh 2018-11-27 337 * Eventually add logic to try multiple slice heights.
> > 5b689599 Gaurav K Singh 2018-11-27 338 */
> > 5b689599 Gaurav K Singh 2018-11-27 339 if (vdsc_cfg->pic_height % 8 == 0)
> > 5b689599 Gaurav K Singh 2018-11-27 340 vdsc_cfg->slice_height = 8;
> > 5b689599 Gaurav K Singh 2018-11-27 341 else if (vdsc_cfg->pic_height % 4 == 0)
> > 5b689599 Gaurav K Singh 2018-11-27 342 vdsc_cfg->slice_height = 4;
> > 5b689599 Gaurav K Singh 2018-11-27 343 else
> > 5b689599 Gaurav K Singh 2018-11-27 344 vdsc_cfg->slice_height = 2;
> > 5b689599 Gaurav K Singh 2018-11-27 345
> > 5b689599 Gaurav K Singh 2018-11-27 346 /* Values filled from DSC Sink DPCD */
> > 5b689599 Gaurav K Singh 2018-11-27 347 vdsc_cfg->dsc_version_major =
> > 5b689599 Gaurav K Singh 2018-11-27 348 (intel_dp->dsc_dpcd[DP_DSC_REV - DP_DSC_SUPPORT] &
> > 5b689599 Gaurav K Singh 2018-11-27 349 DP_DSC_MAJOR_MASK) >> DP_DSC_MAJOR_SHIFT;
> > 5b689599 Gaurav K Singh 2018-11-27 350 vdsc_cfg->dsc_version_minor =
> > 5b689599 Gaurav K Singh 2018-11-27 351 min(DSC_SUPPORTED_VERSION_MIN,
> > 5b689599 Gaurav K Singh 2018-11-27 352 (intel_dp->dsc_dpcd[DP_DSC_REV - DP_DSC_SUPPORT] &
> > 5b689599 Gaurav K Singh 2018-11-27 353 DP_DSC_MINOR_MASK) >> DP_DSC_MINOR_SHIFT);
> > 5b689599 Gaurav K Singh 2018-11-27 354
> > 5b689599 Gaurav K Singh 2018-11-27 355 vdsc_cfg->convert_rgb = intel_dp->dsc_dpcd[DP_DSC_DEC_COLOR_FORMAT_CAP - DP_DSC_SUPPORT] &
> > 5b689599 Gaurav K Singh 2018-11-27 356 DP_DSC_RGB;
> > 5b689599 Gaurav K Singh 2018-11-27 357
> > 5b689599 Gaurav K Singh 2018-11-27 358 line_buf_depth = drm_dp_dsc_sink_line_buf_depth(intel_dp->dsc_dpcd);
> > 5b689599 Gaurav K Singh 2018-11-27 359 if (!line_buf_depth) {
> > 5b689599 Gaurav K Singh 2018-11-27 360 DRM_DEBUG_KMS("DSC Sink Line Buffer Depth invalid\n");
> > 5b689599 Gaurav K Singh 2018-11-27 361 return -EINVAL;
> > 5b689599 Gaurav K Singh 2018-11-27 362 }
> > 5b689599 Gaurav K Singh 2018-11-27 363 if (vdsc_cfg->dsc_version_minor == 2)
> > 5b689599 Gaurav K Singh 2018-11-27 364 vdsc_cfg->line_buf_depth = (line_buf_depth == DSC_1_2_MAX_LINEBUF_DEPTH_BITS) ?
> > 5b689599 Gaurav K Singh 2018-11-27 365 DSC_1_2_MAX_LINEBUF_DEPTH_VAL : line_buf_depth;
> > 5b689599 Gaurav K Singh 2018-11-27 366 else
> > 5b689599 Gaurav K Singh 2018-11-27 367 vdsc_cfg->line_buf_depth = (line_buf_depth > DSC_1_1_MAX_LINEBUF_DEPTH_BITS) ?
> > 5b689599 Gaurav K Singh 2018-11-27 368 DSC_1_1_MAX_LINEBUF_DEPTH_BITS : line_buf_depth;
> > 5b689599 Gaurav K Singh 2018-11-27 369
> > 5b689599 Gaurav K Singh 2018-11-27 370 /* Gen 11 does not support YCbCr */
> > 5b689599 Gaurav K Singh 2018-11-27 371 vdsc_cfg->enable422 = false;
> > 5b689599 Gaurav K Singh 2018-11-27 372 /* Gen 11 does not support VBR */
> > 5b689599 Gaurav K Singh 2018-11-27 373 vdsc_cfg->vbr_enable = false;
> > 5b689599 Gaurav K Singh 2018-11-27 374 vdsc_cfg->block_pred_enable =
> > 5b689599 Gaurav K Singh 2018-11-27 375 intel_dp->dsc_dpcd[DP_DSC_BLK_PREDICTION_SUPPORT - DP_DSC_SUPPORT] &
> > 5b689599 Gaurav K Singh 2018-11-27 376 DP_DSC_BLK_PREDICTION_IS_SUPPORTED;
> > 5b689599 Gaurav K Singh 2018-11-27 377
> > 5b689599 Gaurav K Singh 2018-11-27 378 /* Gen 11 only supports integral values of bpp */
> > 5b689599 Gaurav K Singh 2018-11-27 379 vdsc_cfg->bits_per_pixel = compressed_bpp << 4;
> > 5b689599 Gaurav K Singh 2018-11-27 380 vdsc_cfg->bits_per_component = pipe_config->pipe_bpp / 3;
> > 5b689599 Gaurav K Singh 2018-11-27 381
> > 5b689599 Gaurav K Singh 2018-11-27 382 for (i = 0; i < DSC_NUM_BUF_RANGES - 1; i++) {
> > 5b689599 Gaurav K Singh 2018-11-27 383 /*
> > 5b689599 Gaurav K Singh 2018-11-27 384 * six 0s are appended to the lsb of each threshold value
> > 5b689599 Gaurav K Singh 2018-11-27 385 * internally in h/w.
> > 5b689599 Gaurav K Singh 2018-11-27 386 * Only 8 bits are allowed for programming RcBufThreshold
> > 5b689599 Gaurav K Singh 2018-11-27 387 */
> > 5b689599 Gaurav K Singh 2018-11-27 388 vdsc_cfg->rc_buf_thresh[i] = rc_buf_thresh[i] >> 6;
> > 5b689599 Gaurav K Singh 2018-11-27 389 }
> > 5b689599 Gaurav K Singh 2018-11-27 390
> > 5b689599 Gaurav K Singh 2018-11-27 391 /*
> > 5b689599 Gaurav K Singh 2018-11-27 392 * For 6bpp, RC Buffer threshold 12 and 13 need a different value
> > 5b689599 Gaurav K Singh 2018-11-27 393 * as per C Model
> > 5b689599 Gaurav K Singh 2018-11-27 394 */
> > 5b689599 Gaurav K Singh 2018-11-27 395 if (compressed_bpp == 6) {
> > 5b689599 Gaurav K Singh 2018-11-27 396 vdsc_cfg->rc_buf_thresh[12] = 0x7C;
> > 5b689599 Gaurav K Singh 2018-11-27 397 vdsc_cfg->rc_buf_thresh[13] = 0x7D;
> > 5b689599 Gaurav K Singh 2018-11-27 398 }
> > 5b689599 Gaurav K Singh 2018-11-27 399
> > 5b689599 Gaurav K Singh 2018-11-27 400 row_index = get_row_index_for_rc_params(compressed_bpp);
> > 5b689599 Gaurav K Singh 2018-11-27 401 column_index =
> > 5b689599 Gaurav K Singh 2018-11-27 402 get_column_index_for_rc_params(vdsc_cfg->bits_per_component);
> > 5b689599 Gaurav K Singh 2018-11-27 403
> > 5b689599 Gaurav K Singh 2018-11-27 @404 if (row_index < 0 || column_index < 0)
> >
> > ---
> > 0-DAY kernel test infrastructure Open Source Technology Center
> > https://lists.01.org/pipermail/kbuild-all Intel Corporation
>
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