[PATCH] ath10k: use pre-allocated DMA buffer in Tx

[Kalle Valo]

Peter Oh <poh at qca.qualcomm.com> writes:

> ath10k driver is using dma_pool_alloc per packet and dma_pool_free
> in coresponding at Tx completion.
> Use of pre-allocated DMA buffer in Tx will improve saving CPU resource
> by 5% while it consumes about 56KB memory more as trade off.
>
> Signed-off-by: Peter Oh <poh at qca.qualcomm.com>

I see randomly the warning below with ath.git master branch commit
2e88ba7ebe8d1. Can this patch cause that?

[   53.637883] ------------[ cut here ]------------
[   53.637999] WARNING: CPU: 2 PID: 0 at lib/dma-debug.c:1090 check_unmap+0x815/0x940()
[   53.638070] ath10k_pci 0000:02:00.0: qca99x0 hw2.0 (0x01000000, 0x003801ff bmi 1:1) fw 10.4.1.00007 fwapi 5 bdapi 2 htt-ver 2.2 wmi-op 6 htt-op 4 cal otp max-sta 512 raw 0 hwcrypto 1 features no-p2p
[   53.638077] ath10k_pci 0000:02:00.0: debug 1 debugfs 1 tracing 1 dfs 1 testmode 1
[   53.638205] ath10k_pci 0000:02:00.0: DMA-API: device driver tries to free an invalid DMA memory address
[   53.638270] Modules linked in: ath10k_pci ath10k_core ath mac80211 cfg80211 [last unloaded: cfg80211]
[   53.638800] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.3.0-rc3-wl-ath+ #1082
[   53.638880] Hardware name: Hewlett-Packard HP ProBook 6540b/1722, BIOS 68CDD Ver. F.04 01/27/2010
[   53.638951]  00000000 00000000 f4445de4 c133dd94 00000000 f4445e14 c10562de c1b3e12c
[   53.639551]  f4445e40 00000000 c1b3d3b9 00000442 c13693c5 c13693c5 f422e840 f4445eb4
[   53.640169]  00000000 f4445e2c c10563c3 00000009 f4445e24 c1b3e12c f4445e40 f4445ea4
[   53.640802] Call Trace:
[   53.640874]  [<c133dd94>] dump_stack+0x48/0x64
[   53.640953]  [<c10562de>] warn_slowpath_common+0x8e/0xd0
[   53.641031]  [<c13693c5>] ? check_unmap+0x815/0x940
[   53.641115]  [<c13693c5>] ? check_unmap+0x815/0x940
[   53.641201]  [<c10563c3>] warn_slowpath_fmt+0x33/0x40
[   53.641277]  [<c13693c5>] check_unmap+0x815/0x940
[   53.641356]  [<c1088e35>] ? local_clock+0x25/0x30
[   53.641432]  [<c136974c>] debug_dma_unmap_page+0x8c/0xa0
[   53.641511]  [<fa258aaf>] ath10k_pci_htt_tx_cb+0x8f/0xb0 [ath10k_pci]
[   53.641589]  [<fa258af0>] ath10k_pci_htt_rx_cb+0x20/0x30 [ath10k_pci]
[   53.641668]  [<fa25ca2c>] ath10k_ce_per_engine_service+0x5c/0xa0 [ath10k_pci]
[   53.641746]  [<fa25cae7>] ath10k_ce_per_engine_service_any+0x77/0x90 [ath10k_pci]
[   53.641825]  [<fa25aa4b>] ath10k_pci_tasklet+0x1b/0x50 [ath10k_pci]
[   53.642064]  [<c105bc4e>] tasklet_action+0x9e/0xb0
[   53.642142]  [<c105b17b>] __do_softirq+0xbb/0x3c0
[   53.642222]  [<c105b0c0>] ? trace_event_raw_event_irq_handler_entry+0xa0/0xa0
[   53.642300]  [<c10059b9>] do_softirq_own_stack+0x29/0x40
[   53.642375]  <IRQ>  [<c105b716>] irq_exit+0x86/0xb0
[   53.642526]  [<c18c2310>] do_IRQ+0x60/0x120
[   53.642604]  [<c10a4deb>] ? trace_hardirqs_off+0xb/0x10
[   53.642680]  [<c18c1931>] common_interrupt+0x31/0x38
[   53.642760]  [<c1694fa9>] ? cpuidle_enter_state+0xc9/0x350
[   53.642835]  [<c1696879>] ? menu_select+0x239/0x4b0
[   53.642925]  [<c1695264>] cpuidle_enter+0x14/0x20
[   53.643063]  [<c109becc>] call_cpuidle+0x3c/0x70
[   53.643140]  [<c109c0a9>] cpu_startup_entry+0x1a9/0x390
[   53.643218]  [<c1038b75>] start_secondary+0x105/0x150
[   53.643294] ---[ end trace a5dc1d40148089eb ]---

-- 
Kalle Valo