Hi Daniel, I love your patch! Yet something to improve: [auto build test ERROR on tegra-drm/drm/tegra/for-next] [also build test ERROR on drm/drm-next linus/master v5.17-rc2 next-20220131] [cannot apply to airlied/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/Daniel-Vetter/some-fbcon-patches-mostly-locking/20220201-050907 base: git://anongit.freedesktop.org/tegra/linux.git drm/tegra/for-next config: i386-allyesconfig (https://download.01.org/0day-ci/archive/20220201/202202011603.vczWPod7-lkp@intel.com/config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://github.com/0day-ci/linux/commit/245da5ab93b17c0cf1521713d5bde655a72efb65 git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Daniel-Vetter/some-fbcon-patches-mostly-locking/20220201-050907 git checkout 245da5ab93b17c0cf1521713d5bde655a72efb65 # save the config file to linux build tree mkdir build_dir make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All errors (new ones prefixed by >>): drivers/staging/olpc_dcon/olpc_dcon.c: In function 'dcon_probe': >> drivers/staging/olpc_dcon/olpc_dcon.c:605:6: error: 'num_registered_fb' undeclared (first use in this function); did you mean 'WB_registered'? 605 | if (num_registered_fb < 1) { | ^~~~~~~~~~~~~~~~~ | WB_registered drivers/staging/olpc_dcon/olpc_dcon.c:605:6: note: each undeclared identifier is reported only once for each function it appears in >> drivers/staging/olpc_dcon/olpc_dcon.c:610:17: error: 'registered_fb' undeclared (first use in this function) 610 | dcon->fbinfo = registered_fb[0]; | ^~~~~~~~~~~~~ vim +605 drivers/staging/olpc_dcon/olpc_dcon.c 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 584 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 585 static int dcon_probe(struct i2c_client *client, const struct i2c_device_id *id) 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 586 { 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 587 struct dcon_priv *dcon; 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 588 int rc, i, j; 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 589 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 590 if (!pdata) 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 591 return -ENXIO; 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 592 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 593 dcon = kzalloc(sizeof(*dcon), GFP_KERNEL); 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 594 if (!dcon) 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 595 return -ENOMEM; 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 596 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 597 dcon->client = client; 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 598 init_waitqueue_head(&dcon->waitq); 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 599 INIT_WORK(&dcon->switch_source, dcon_source_switch); 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 600 dcon->reboot_nb.notifier_call = dcon_reboot_notify; 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 601 dcon->reboot_nb.priority = -1; 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 602 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 603 i2c_set_clientdata(client, dcon); 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 604 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 @605 if (num_registered_fb < 1) { 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 606 dev_err(&client->dev, "DCON driver requires a registered fb\n"); 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 607 rc = -EIO; 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 608 goto einit; 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 609 } 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 @610 dcon->fbinfo = registered_fb[0]; 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 611 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 612 rc = dcon_hw_init(dcon, 1); 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 613 if (rc) 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 614 goto einit; 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 615 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 616 /* Add the DCON device */ 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 617 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 618 dcon_device = platform_device_alloc("dcon", -1); 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 619 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 620 if (!dcon_device) { 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 621 pr_err("Unable to create the DCON device\n"); 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 622 rc = -ENOMEM; 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 623 goto eirq; 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 624 } 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 625 rc = platform_device_add(dcon_device); 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 626 platform_set_drvdata(dcon_device, dcon); 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 627 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 628 if (rc) { 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 629 pr_err("Unable to add the DCON device\n"); 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 630 goto edev; 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 631 } 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 632 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 633 for (i = 0; i < ARRAY_SIZE(dcon_device_files); i++) { 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 634 rc = device_create_file(&dcon_device->dev, 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 635 &dcon_device_files[i]); 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 636 if (rc) { 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 637 dev_err(&dcon_device->dev, "Cannot create sysfs file\n"); 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 638 goto ecreate; 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 639 } 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 640 } 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 641 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 642 dcon->bl_val = dcon_read(dcon, DCON_REG_BRIGHT) & 0x0F; 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 643 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 644 /* Add the backlight device for the DCON */ 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 645 dcon_bl_props.brightness = dcon->bl_val; 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 646 dcon->bl_dev = backlight_device_register("dcon-bl", &dcon_device->dev, 848d9eabcaebf21 Zebulon McCorkle 2017-11-21 647 dcon, &dcon_bl_ops, 848d9eabcaebf21 Zebulon McCorkle 2017-11-21 648 &dcon_bl_props); 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 649 if (IS_ERR(dcon->bl_dev)) { 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 650 dev_err(&client->dev, "cannot register backlight dev (%ld)\n", 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 651 PTR_ERR(dcon->bl_dev)); 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 652 dcon->bl_dev = NULL; 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 653 } 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 654 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 655 register_reboot_notifier(&dcon->reboot_nb); 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 656 atomic_notifier_chain_register(&panic_notifier_list, &dcon_panic_nb); 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 657 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 658 return 0; 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 659 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 660 ecreate: 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 661 for (j = 0; j < i; j++) 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 662 device_remove_file(&dcon_device->dev, &dcon_device_files[j]); 4996b4610767064 Jing Xiangfeng 2020-11-20 663 platform_device_del(dcon_device); 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 664 edev: 4996b4610767064 Jing Xiangfeng 2020-11-20 665 platform_device_put(dcon_device); 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 666 dcon_device = NULL; 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 667 eirq: 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 668 free_irq(DCON_IRQ, dcon); 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 669 einit: 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 670 kfree(dcon); 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 671 return rc; 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 672 } 53c43c5ca13328a Greg Kroah-Hartman 2016-04-04 673 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org