Hi Thomas, I love your patch! Perhaps something to improve: [auto build test WARNING on ebea934e2651857c9b56cc80bf99460ee18a3592] url: https://github.com/intel-lab-lkp/linux/commits/Thomas-Zimmermann/fbdev-Maintain-device-ownership-with-aperture-helpers/20220718-152559 base: ebea934e2651857c9b56cc80bf99460ee18a3592 config: x86_64-randconfig-a003 (https://download.01.org/0day-ci/archive/20220718/202207181701.mB5xBuhX-lkp@xxxxxxxxx/config) compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project d74b88c69dc2644bd0dc5d64e2d7413a0d4040e5) 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/intel-lab-lkp/linux/commit/64ab1ffe4e3accdef429db81ec645a1cbad540df git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Thomas-Zimmermann/fbdev-Maintain-device-ownership-with-aperture-helpers/20220718-152559 git checkout 64ab1ffe4e3accdef429db81ec645a1cbad540df # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/video/fbdev/ If you fix the issue, kindly add following tag where applicable Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): >> drivers/video/fbdev/hyperv_fb.c:1080:26: warning: expression which evaluates to zero treated as a null pointer constant of type 'const char *' [-Wnon-literal-null-conversion] KBUILD_MODNAME, false); ^~~~~ 1 warning generated. vim +1080 drivers/video/fbdev/hyperv_fb.c 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 987 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 988 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 989 /* Get framebuffer memory from Hyper-V video pci space */ 3546448338e76a drivers/video/fbdev/hyperv_fb.c Jake Oshins 2015-08-05 990 static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info) 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 991 { 9069fd54960304 drivers/video/hyperv_fb.c Gerd Hoffmann 2014-02-26 992 struct hvfb_par *par = info->par; 9069fd54960304 drivers/video/hyperv_fb.c Gerd Hoffmann 2014-02-26 993 struct pci_dev *pdev = NULL; 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 994 void __iomem *fb_virt; 9069fd54960304 drivers/video/hyperv_fb.c Gerd Hoffmann 2014-02-26 995 int gen2vm = efi_enabled(EFI_BOOT); 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 996 phys_addr_t paddr; 9069fd54960304 drivers/video/hyperv_fb.c Gerd Hoffmann 2014-02-26 997 int ret; 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 998 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 999 info->apertures = alloc_apertures(1); 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1000 if (!info->apertures) 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1001 return -ENOMEM; d21987d709e807 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-09-18 1002 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1003 if (!gen2vm) { 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1004 pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT, 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1005 PCI_DEVICE_ID_HYPERV_VIDEO, NULL); 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1006 if (!pdev) { 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1007 pr_err("Unable to find PCI Hyper-V video\n"); 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1008 return -ENODEV; 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1009 } 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1010 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1011 info->apertures->ranges[0].base = pci_resource_start(pdev, 0); 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1012 info->apertures->ranges[0].size = pci_resource_len(pdev, 0); 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1013 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1014 /* 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1015 * For Gen 1 VM, we can directly use the contiguous memory 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1016 * from VM. If we succeed, deferred IO happens directly 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1017 * on this allocated framebuffer memory, avoiding extra 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1018 * memory copy. 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1019 */ 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1020 paddr = hvfb_get_phymem(hdev, screen_fb_size); 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1021 if (paddr != (phys_addr_t) -1) { 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1022 par->mmio_pp = paddr; 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1023 par->mmio_vp = par->dio_vp = __va(paddr); 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1024 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1025 info->fix.smem_start = paddr; 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1026 info->fix.smem_len = screen_fb_size; 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1027 info->screen_base = par->mmio_vp; 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1028 info->screen_size = screen_fb_size; 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1029 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1030 par->need_docopy = false; 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1031 goto getmem_done; 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1032 } 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1033 pr_info("Unable to allocate enough contiguous physical memory on Gen 1 VM. Using MMIO instead.\n"); 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1034 } else { 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1035 info->apertures->ranges[0].base = screen_info.lfb_base; 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1036 info->apertures->ranges[0].size = screen_info.lfb_size; 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1037 } 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1038 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1039 /* 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1040 * Cannot use the contiguous physical memory. 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1041 * Allocate mmio space for framebuffer. 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1042 */ 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1043 dio_fb_size = 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1044 screen_width * screen_height * screen_depth / 8; 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1045 c4b4d7047f16a8 drivers/video/fbdev/hyperv_fb.c Saurabh Sengar 2022-04-27 1046 ret = vmbus_allocate_mmio(&par->mem, hdev, 0, -1, 3546448338e76a drivers/video/fbdev/hyperv_fb.c Jake Oshins 2015-08-05 1047 screen_fb_size, 0x100000, true); 9069fd54960304 drivers/video/hyperv_fb.c Gerd Hoffmann 2014-02-26 1048 if (ret != 0) { 3546448338e76a drivers/video/fbdev/hyperv_fb.c Jake Oshins 2015-08-05 1049 pr_err("Unable to allocate framebuffer memory\n"); 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1050 goto err1; 9069fd54960304 drivers/video/hyperv_fb.c Gerd Hoffmann 2014-02-26 1051 } 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1052 5f1251a48c17b5 drivers/video/fbdev/hyperv_fb.c Dexuan Cui 2020-11-17 1053 /* 5f1251a48c17b5 drivers/video/fbdev/hyperv_fb.c Dexuan Cui 2020-11-17 1054 * Map the VRAM cacheable for performance. This is also required for 5f1251a48c17b5 drivers/video/fbdev/hyperv_fb.c Dexuan Cui 2020-11-17 1055 * VM Connect to display properly for ARM64 Linux VM, as the host also 5f1251a48c17b5 drivers/video/fbdev/hyperv_fb.c Dexuan Cui 2020-11-17 1056 * maps the VRAM cacheable. 5f1251a48c17b5 drivers/video/fbdev/hyperv_fb.c Dexuan Cui 2020-11-17 1057 */ 5f1251a48c17b5 drivers/video/fbdev/hyperv_fb.c Dexuan Cui 2020-11-17 1058 fb_virt = ioremap_cache(par->mem->start, screen_fb_size); 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1059 if (!fb_virt) 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1060 goto err2; 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1061 d21987d709e807 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-09-18 1062 /* Allocate memory for deferred IO */ d21987d709e807 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-09-18 1063 par->dio_vp = vzalloc(round_up(dio_fb_size, PAGE_SIZE)); d21987d709e807 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-09-18 1064 if (par->dio_vp == NULL) d21987d709e807 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-09-18 1065 goto err3; d21987d709e807 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-09-18 1066 d21987d709e807 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-09-18 1067 /* Physical address of FB device */ d21987d709e807 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-09-18 1068 par->mmio_pp = par->mem->start; d21987d709e807 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-09-18 1069 /* Virtual address of FB device */ d21987d709e807 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-09-18 1070 par->mmio_vp = (unsigned char *) fb_virt; d21987d709e807 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-09-18 1071 3546448338e76a drivers/video/fbdev/hyperv_fb.c Jake Oshins 2015-08-05 1072 info->fix.smem_start = par->mem->start; d21987d709e807 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-09-18 1073 info->fix.smem_len = dio_fb_size; d21987d709e807 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-09-18 1074 info->screen_base = par->dio_vp; d21987d709e807 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-09-18 1075 info->screen_size = dio_fb_size; 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1076 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 1077 getmem_done: 64ab1ffe4e3acc drivers/video/fbdev/hyperv_fb.c Thomas Zimmermann 2022-07-18 1078 aperture_remove_conflicting_devices(info->apertures->ranges[0].base, 64ab1ffe4e3acc drivers/video/fbdev/hyperv_fb.c Thomas Zimmermann 2022-07-18 1079 info->apertures->ranges[0].size, 3a6fb6c4255c38 drivers/video/fbdev/hyperv_fb.c Wei Hu 2019-12-09 @1080 KBUILD_MODNAME, false); 3cb73bc3fa2a3c drivers/video/fbdev/hyperv_fb.c Kairui Song 2020-10-14 1081 3cb73bc3fa2a3c drivers/video/fbdev/hyperv_fb.c Kairui Song 2020-10-14 1082 if (gen2vm) { 3cb73bc3fa2a3c drivers/video/fbdev/hyperv_fb.c Kairui Song 2020-10-14 1083 /* framebuffer is reallocated, clear screen_info to avoid misuse from kexec */ 3cb73bc3fa2a3c drivers/video/fbdev/hyperv_fb.c Kairui Song 2020-10-14 1084 screen_info.lfb_size = 0; 3cb73bc3fa2a3c drivers/video/fbdev/hyperv_fb.c Kairui Song 2020-10-14 1085 screen_info.lfb_base = 0; 3cb73bc3fa2a3c drivers/video/fbdev/hyperv_fb.c Kairui Song 2020-10-14 1086 screen_info.orig_video_isVGA = 0; 3cb73bc3fa2a3c drivers/video/fbdev/hyperv_fb.c Kairui Song 2020-10-14 1087 } else { 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1088 pci_dev_put(pdev); 3cb73bc3fa2a3c drivers/video/fbdev/hyperv_fb.c Kairui Song 2020-10-14 1089 } 9069fd54960304 drivers/video/hyperv_fb.c Gerd Hoffmann 2014-02-26 1090 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1091 return 0; 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1092 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1093 err3: 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1094 iounmap(fb_virt); 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1095 err2: 696ca5e82c057a drivers/video/fbdev/hyperv_fb.c Jake Oshins 2016-04-05 1096 vmbus_free_mmio(par->mem->start, screen_fb_size); 3546448338e76a drivers/video/fbdev/hyperv_fb.c Jake Oshins 2015-08-05 1097 par->mem = NULL; 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1098 err1: 9069fd54960304 drivers/video/hyperv_fb.c Gerd Hoffmann 2014-02-26 1099 if (!gen2vm) 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1100 pci_dev_put(pdev); 9069fd54960304 drivers/video/hyperv_fb.c Gerd Hoffmann 2014-02-26 1101 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1102 return -ENOMEM; 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1103 } 68a2d20b79b105 drivers/video/hyperv_fb.c Haiyang Zhang 2013-04-29 1104 -- 0-DAY CI Kernel Test Service https://01.org/lkp