Hi Thierry, On 21/01/2015 11:50, Thierry Reding wrote: > On Wed, Jan 21, 2015 at 12:03:41AM +0000, Paul Walmsley wrote: >> (linux-ide@ added) >> >> Commit c7d7ddee7e24eedde6149eefbcfbfbc7125b9ff0 ("ata: libahci: Allow >> using multiple regulators") in Linux-next 20150120 causes a panic >> during boot on multiple Tegra boards: >> >> http://nvt.pwsan.com/experimental/linux-next/testlogs/test_next-20150120/20150120001539/boot/tegra30-beaver/tegra30-beaver/tegra_defconfig_log.txt >> http://nvt.pwsan.com/experimental/linux-next/testlogs/test_next-20150120/20150120001539/boot/tegra114-dalmore-a04/tegra114-dalmore/tegra_defconfig_log.txt >> http://nvt.pwsan.com/experimental/linux-next/testlogs/test_next-20150120/20150120001539/boot/tegra124-jetson-tk1/tegra124-jetson-tk1/tegra_defconfig_log.txt >> >> Taking the latter boot log as an example, the 6b6b6b9f value that the >> kernel is trying to dereference is being passed into _regulator_put() as a >> struct regulator *. >> >> >> - Paul >> > > Here's the devres log of what's happening: > > [ 4.949689] tegra-ahci 70027000.sata: DEVRES ADD ee1e2a00 devm_kzalloc_release (16 bytes) > [ 4.957886] tegra-ahci 70027000.sata: DEVRES ADD ee1e29c0 devm_pinctrl_release (4 bytes) > [ 4.965984] tegra-ahci 70027000.sata: DEVRES REM ee1e29c0 devm_pinctrl_release (4 bytes) > [ 4.974079] tegra-ahci 70027000.sata: DEVRES REM ee1e2a00 devm_kzalloc_release (16 bytes) > [ 4.982298] tegra-ahci 70027000.sata: DEVRES ADD ee1e29c0 grp< (0 bytes) > [ 4.989006] tegra-ahci 70027000.sata: DEVRES ADD ee1dae00 ahci_platform_put_resources (96 bytes) > [ 4.997784] tegra-ahci 70027000.sata: DEVRES ADD ee1e2980 devm_region_release (12 bytes) > [ 5.005879] tegra-ahci 70027000.sata: DEVRES ADD ee1e2900 devm_ioremap_release (4 bytes) > [ 5.014005] tegra-ahci 70027000.sata: DEVRES ADD ee1e28c0 devm_kzalloc_release (4 bytes) > [ 5.022096] tegra-ahci 70027000.sata: DEVRES ADD ee1e2880 devm_kzalloc_release (4 bytes) > [ 5.030209] tegra-ahci 70027000.sata: DEVRES ADD ee1e2840 devm_phy_release (4 bytes) > [ 5.037952] tegra-ahci 70027000.sata: DEVRES REM ee1e29c0 grp< (0 bytes) > [ 5.044660] tegra-ahci 70027000.sata: DEVRES ADD ee1dad80 devm_kzalloc_release (84 bytes) > [ 5.052845] tegra-ahci 70027000.sata: DEVRES ADD ee1e29c0 devm_region_release (12 bytes) > [ 5.060938] tegra-ahci 70027000.sata: DEVRES ADD ee1e2f80 devm_ioremap_release (4 bytes) > [ 5.069039] tegra-ahci 70027000.sata: DEVRES ADD ee1e2f40 devm_reset_control_release (4 bytes) > [ 5.077647] tegra-ahci 70027000.sata: DEVRES ADD ee1e2ec0 devm_reset_control_release (4 bytes) > [ 5.086271] tegra-ahci 70027000.sata: DEVRES ADD ee1e2e40 devm_reset_control_release (4 bytes) > [ 5.094890] tegra-ahci 70027000.sata: DEVRES ADD ee1e2dc0 devm_clk_release (4 bytes) > [ 5.102659] tegra-ahci 70027000.sata: Failed to get supply 'avdd': -517 > [ 5.109276] tegra-ahci 70027000.sata: Failed to get regulators > [ 5.115103] tegra-ahci 70027000.sata: DEVRES REL ee1e2dc0 devm_clk_release (4 bytes) > [ 5.122850] tegra-ahci 70027000.sata: DEVRES REL ee1e2e40 devm_reset_control_release (4 bytes) > [ 5.131462] tegra-ahci 70027000.sata: DEVRES REL ee1e2ec0 devm_reset_control_release (4 bytes) > [ 5.140073] tegra-ahci 70027000.sata: DEVRES REL ee1e2f40 devm_reset_control_release (4 bytes) > [ 5.148672] tegra-ahci 70027000.sata: DEVRES REL ee1e2f80 devm_ioremap_release (4 bytes) > [ 5.156764] tegra-ahci 70027000.sata: DEVRES REL ee1e29c0 devm_region_release (12 bytes) > [ 5.164856] tegra-ahci 70027000.sata: DEVRES REL ee1dad80 devm_kzalloc_release (84 bytes) > [ 5.173034] tegra-ahci 70027000.sata: DEVRES REL ee1e2840 devm_phy_release (4 bytes) > [ 5.180778] tegra-ahci 70027000.sata: DEVRES REL ee1e2880 devm_kzalloc_release (4 bytes) > [ 5.188868] tegra-ahci 70027000.sata: DEVRES REL ee1e28c0 devm_kzalloc_release (4 bytes) > [ 5.196948] tegra-ahci 70027000.sata: DEVRES REL ee1e2900 devm_ioremap_release (4 bytes) > [ 5.205037] tegra-ahci 70027000.sata: DEVRES REL ee1e2980 devm_region_release (12 bytes) > [ 5.213129] tegra-ahci 70027000.sata: DEVRES REL ee1dae00 ahci_platform_put_resources (96 bytes) > > What's happening here is that ahci_platform_put_resources() is added to > the devres list before the devm_kzalloc() that allocates the target_pwrs > array, which causes the target_pwrs array to be freed before devres gets > to call ahci_platform_put_resources(). > > Mixing managed and non-managed resources this way doesn't work, so I had > to apply the attached patch to fix this. > > Tejun, preferably the attached patch should be squashed into commit > c7d7ddee7e24 ("ata: libahci: Allow using multiple regulators") to avoid > breaking bisectability. If you don't want to rewrite history, let me > know and I can turn it into a proper patch. Thanks having took care of it. I tested your patch and it didn't introduce any regression on the board I tested. Gregory -- Gregory Clement, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html