If MHI power up fails, for instance due to a missing firmware file, ath11k_core_init() does not power down the device on this error, the MHI controller stays prepared, and the MHI device context and the RDDM image table allocated by mhi_prepare_for_power_up() are not released, here is a report from kmemleak: % cat /sys/kernel/debug/kmemleak unreferenced object 0xffff00079156a140 (size 64): comm "(udev-worker)", pid 595, jiffies 4294893781 hex dump (first 32 bytes): 00 d0 f1 80 00 80 ff ff 00 50 f1 80 00 80 ff ff .........P...... 00 d0 f7 80 00 80 ff ff 00 30 fc ff 00 00 00 00 .........0...... backtrace (crc 62662f0a): kmemleak_alloc+0x34/0x40 __kmalloc_cache_noprof+0x224/0x3b8 mhi_prepare_for_power_up+0x58/0x548 [mhi] ath11k_mhi_start+0x30/0xb8 [ath11k_pci] ath11k_pci_power_up+0xcc/0x188 [ath11k_pci] ath11k_core_init+0x8c/0x190 [ath11k] ath11k_pci_probe+0x4e0/0x870 [ath11k_pci] local_pci_probe+0x40/0xa8 pci_call_probe+0x64/0x190 pci_device_probe+0xac/0x138 really_probe+0xbc/0x298 __driver_probe_device+0x16c/0x19c driver_probe_device+0x3c/0x114 __driver_attach+0x98/0x19c bus_for_each_dev+0x74/0xd0 driver_attach+0x24/0x30 unreferenced object 0xffff0007916fb800 (size 512): comm "(udev-worker)", pid 595, jiffies 4294893781 hex dump (first 32 bytes): 00 60 04 81 00 80 ff ff 0a 00 00 00 00 00 00 00 .`.............. 00 10 e0 82 00 80 ff ff 00 00 00 00 00 00 00 00 ................ backtrace (crc 52e9e075): kmemleak_alloc+0x34/0x40 __kmalloc_noprof+0x280/0x440 mhi_alloc_bhie_table+0x54/0x168 [mhi] mhi_prepare_for_power_up+0x318/0x548 [mhi] ath11k_mhi_start+0x30/0xb8 [ath11k_pci] ath11k_pci_power_up+0xcc/0x188 [ath11k_pci] ath11k_core_init+0x8c/0x190 [ath11k] ath11k_pci_probe+0x4e0/0x870 [ath11k_pci] local_pci_probe+0x40/0xa8 pci_call_probe+0x64/0x190 pci_device_probe+0xac/0x138 really_probe+0xbc/0x298 __driver_probe_device+0x16c/0x19c driver_probe_device+0x3c/0x114 __driver_attach+0x98/0x19c bus_for_each_dev+0x74/0xd0 Track the prepared state of MHI in a new ab_pci flag, and unprepare it in ath11k_mhi_unregister() if it is still set. The prepared state is intentionally kept on power up failure, because the RDDM image may still be read by a firmware crash dump collection in the reset work. After a failed power up in the reset or resume path the device stays bound, and ath11k_mhi_stop() releases the resources on the next power down, as before. Also unprepare MHI in ath11k_mhi_stop() only if the flag is set. If mhi_prepare_for_power_up() fails in the reset or resume path, it releases the device context on its own error path, and the unconditional mhi_unprepare_after_power_down() in a later ath11k_mhi_stop() frees the command ring buffers again and dereferences the NULL device context. Fixes: 3df6d74aedfd ("ath11k: mhi: use mhi_sync_power_up()") Signed-off-by: Vladimir Zapolskiy --- drivers/net/wireless/ath/ath11k/mhi.c | 9 ++++++++- drivers/net/wireless/ath/ath11k/pci.h | 1 + 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/ath/ath11k/mhi.c b/drivers/net/wireless/ath/ath11k/mhi.c index a6c9ff112c68..7cc652292d6f 100644 --- a/drivers/net/wireless/ath/ath11k/mhi.c +++ b/drivers/net/wireless/ath/ath11k/mhi.c @@ -425,6 +425,10 @@ void ath11k_mhi_unregister(struct ath11k_pci *ab_pci) { struct mhi_controller *mhi_ctrl = ab_pci->mhi_ctrl; + /* MHI stays prepared after a failed power up */ + if (test_and_clear_bit(ATH11K_PCI_MHI_PREPARED, &ab_pci->flags)) + mhi_unprepare_after_power_down(mhi_ctrl); + mhi_unregister_controller(mhi_ctrl); kfree(mhi_ctrl->irq); mhi_free_controller(mhi_ctrl); @@ -443,6 +447,8 @@ int ath11k_mhi_start(struct ath11k_pci *ab_pci) return ret; } + set_bit(ATH11K_PCI_MHI_PREPARED, &ab_pci->flags); + ret = mhi_sync_power_up(ab_pci->mhi_ctrl); if (ret) { ath11k_warn(ab, "failed to power up mhi: %d", ret); @@ -463,7 +469,8 @@ void ath11k_mhi_stop(struct ath11k_pci *ab_pci, bool is_suspend) else mhi_power_down(ab_pci->mhi_ctrl, true); - mhi_unprepare_after_power_down(ab_pci->mhi_ctrl); + if (test_and_clear_bit(ATH11K_PCI_MHI_PREPARED, &ab_pci->flags)) + mhi_unprepare_after_power_down(ab_pci->mhi_ctrl); } int ath11k_mhi_suspend(struct ath11k_pci *ab_pci) diff --git a/drivers/net/wireless/ath/ath11k/pci.h b/drivers/net/wireless/ath/ath11k/pci.h index 1e3005a4b64c..1e811245c1a5 100644 --- a/drivers/net/wireless/ath/ath11k/pci.h +++ b/drivers/net/wireless/ath/ath11k/pci.h @@ -55,6 +55,7 @@ enum ath11k_pci_flags { ATH11K_PCI_ASPM_RESTORE, + ATH11K_PCI_MHI_PREPARED, }; struct ath11k_pci { -- 2.51.0