[PATCH] wifi: ath11k: Unprepare MHI on power up failure

[Vladimir Zapolskiy]

If MHI power up fails, for instance it happens due to a missing firmware,
ath11k_mhi_start() returns without undoing mhi_prepare_for_power_up().
Then the failed probe or power up unwinding frees the MHI controller,
but the MHI device context and the RDDM image table allocated by
mhi_prepare_for_power_up() are leaked along with their DMA buffers:

  % 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

The MHI device is already powered down by mhi_sync_power_up() on
failure, but mhi_unprepare_after_power_down() still has to be
called on error path to release the allocated resources.

Fixes: 3df6d74aedfd ("ath11k: mhi: use mhi_sync_power_up()")
Signed-off-by: Vladimir Zapolskiy <vz at kernel.org>
---
 drivers/net/wireless/ath/ath11k/mhi.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/wireless/ath/ath11k/mhi.c b/drivers/net/wireless/ath/ath11k/mhi.c
index a6c9ff112c68..76c194573ec7 100644
--- a/drivers/net/wireless/ath/ath11k/mhi.c
+++ b/drivers/net/wireless/ath/ath11k/mhi.c
@@ -446,6 +446,7 @@ int ath11k_mhi_start(struct ath11k_pci *ab_pci)
 	ret = mhi_sync_power_up(ab_pci->mhi_ctrl);
 	if (ret) {
 		ath11k_warn(ab, "failed to power up mhi: %d", ret);
+		mhi_unprepare_after_power_down(ab_pci->mhi_ctrl);
 		return ret;
 	}
 
-- 
2.51.0