Hi Giulio, Thank you for the patch! Yet something to improve: [auto build test ERROR on sunxi/sunxi/for-next] [also build test ERROR on drm-exynos/exynos-drm-next drm-intel/for-linux-next tegra-drm/drm/tegra/for-next drm-tip/drm-tip v5.11-rc3 next-20210113] [cannot apply to mripard/sunxi/for-next drm/drm-next] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Giulio-Benetti/drm-sun4i-tcon-fi... base: https://git.kernel.org/pub/scm/linux/kernel/git/sunxi/linux.git sunxi/for-next config: arm64-randconfig-r005-20210113 (attached as .config) compiler: aarch64-linux-gcc (GCC) 9.3.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/0day-ci/linux/commit/acbc865cfd67e02cb2e4a37dfd56598ee... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Giulio-Benetti/drm-sun4i-tcon-fix-inverted-DCLK-polarity/20210114-001027 git checkout acbc865cfd67e02cb2e4a37dfd56598eeae38287 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): drivers/gpu/drm/sun4i/sun4i_tcon.c: In function 'sun4i_tcon0_mode_set_rgb': 578 | SUN4I_TCON0_IO_POL_DCLK_DRIVE_NEGDGE | | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | SUN4I_TCON0_IO_POL_DCLK_DRIVE_NEGEDGE drivers/gpu/drm/sun4i/sun4i_tcon.c:578:7: note: each undeclared identifier is reported only once for each function it appears in vim +578 drivers/gpu/drm/sun4i/sun4i_tcon.c 502 503 static void sun4i_tcon0_mode_set_rgb(struct sun4i_tcon *tcon, 504 const struct drm_encoder *encoder, 505 const struct drm_display_mode *mode) 506 { 507 struct drm_connector *connector = sun4i_tcon_get_connector(encoder); 508 const struct drm_display_info *info = &connector->display_info; 509 unsigned int bp, hsync, vsync; 510 u8 clk_delay; 511 u32 val = 0; 512 513 WARN_ON(!tcon->quirks->has_channel_0); 514 515 tcon->dclk_min_div = tcon->quirks->dclk_min_div; 516 tcon->dclk_max_div = 127; 517 sun4i_tcon0_mode_set_common(tcon, mode); 518 519 /* Set dithering if needed */ 520 sun4i_tcon0_mode_set_dithering(tcon, connector); 521 522 /* Adjust clock delay */ 523 clk_delay = sun4i_tcon_get_clk_delay(mode, 0); 524 regmap_update_bits(tcon->regs, SUN4I_TCON0_CTL_REG, 525 SUN4I_TCON0_CTL_CLK_DELAY_MASK, 526 SUN4I_TCON0_CTL_CLK_DELAY(clk_delay)); 527 528 /* 529 * This is called a backporch in the register documentation, 530 * but it really is the back porch + hsync 531 */ 532 bp = mode->crtc_htotal - mode->crtc_hsync_start; 533 DRM_DEBUG_DRIVER("Setting horizontal total %d, backporch %d\n", 534 mode->crtc_htotal, bp); 535 536 /* Set horizontal display timings */ 537 regmap_write(tcon->regs, SUN4I_TCON0_BASIC1_REG, 538 SUN4I_TCON0_BASIC1_H_TOTAL(mode->crtc_htotal) | 539 SUN4I_TCON0_BASIC1_H_BACKPORCH(bp)); 540 541 /* 542 * This is called a backporch in the register documentation, 543 * but it really is the back porch + hsync 544 */ 545 bp = mode->crtc_vtotal - mode->crtc_vsync_start; 546 DRM_DEBUG_DRIVER("Setting vertical total %d, backporch %d\n", 547 mode->crtc_vtotal, bp); 548 549 /* Set vertical display timings */ 550 regmap_write(tcon->regs, SUN4I_TCON0_BASIC2_REG, 551 SUN4I_TCON0_BASIC2_V_TOTAL(mode->crtc_vtotal * 2) | 552 SUN4I_TCON0_BASIC2_V_BACKPORCH(bp)); 553 554 /* Set Hsync and Vsync length */ 555 hsync = mode->crtc_hsync_end - mode->crtc_hsync_start; 556 vsync = mode->crtc_vsync_end - mode->crtc_vsync_start; 557 DRM_DEBUG_DRIVER("Setting HSYNC %d, VSYNC %d\n", hsync, vsync); 558 regmap_write(tcon->regs, SUN4I_TCON0_BASIC3_REG, 559 SUN4I_TCON0_BASIC3_V_SYNC(vsync) | 560 SUN4I_TCON0_BASIC3_H_SYNC(hsync)); 561 562 /* Setup the polarity of the various signals */ 563 if (mode->flags & DRM_MODE_FLAG_PHSYNC) 564 val |= SUN4I_TCON0_IO_POL_HSYNC_POSITIVE; 565 566 if (mode->flags & DRM_MODE_FLAG_PVSYNC) 567 val |= SUN4I_TCON0_IO_POL_VSYNC_POSITIVE; 568 569 if (info->bus_flags & DRM_BUS_FLAG_DE_LOW) 570 val |= SUN4I_TCON0_IO_POL_DE_NEGATIVE; 571 572 if (info->bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE) 573 val |= SUN4I_TCON0_IO_POL_DCLK_DRIVE_NEGEDGE; 574 575 regmap_update_bits(tcon->regs, SUN4I_TCON0_IO_POL_REG, 576 SUN4I_TCON0_IO_POL_HSYNC_POSITIVE | 577 SUN4I_TCON0_IO_POL_VSYNC_POSITIVE | 579 SUN4I_TCON0_IO_POL_DE_NEGATIVE, 580 val); 581 582 /* Map output pins to channel 0 */ 583 regmap_update_bits(tcon->regs, SUN4I_TCON_GCTL_REG, 584 SUN4I_TCON_GCTL_IOMAP_MASK, 585 SUN4I_TCON_GCTL_IOMAP_TCON0); 586 587 /* Enable the output on the pins */ 588 regmap_write(tcon->regs, SUN4I_TCON0_IO_TRI_REG, 0); 589 } 590 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org