2019-12-12 07:51:32

by Zhi Chen

Subject: [PATCH,v3] Revert "ath10k: fix DMA related firmware crashes on multiple devices"

This reverts commit 76d164f582150fd0259ec0fcbc485470bcd8033e.
PCIe hung issue was observed on multiple platforms. The issue was
reproduced
when DUT was configured as AP and associated with 50+ STAs.

For QCA9984/QCA9888, the DMA_BURST_SIZE register controls the AXI burst
size
of the RD/WR access to the HOST MEM.
0 - No split , RAW read/write transfer size from MAC is put out on bus
as burst length
1 - Split at 256 byte boundary
2,3 - Reserved

With PCIe protocol analyzer, we can see DMA Read crossing 4KB boundary
when
issue happened. It broke PCIe spec and caused PCIe stuck. So revert
the default value from 0 to 1.

Tested: IPQ8064 + QCA9984 with firmware 10.4-3.10-00047
QCS404 + QCA9984 with firmware 10.4-3.9.0.2--00044
Synaptics AS370 + QCA9888 with firmware 10.4-3.9.0.2--00040

Signed-off-by: Zhi Chen <[email protected]>
---
v2: restored 10.2 register configuration
v3: modified commit message
---
drivers/net/wireless/ath/ath10k/hw.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath10k/hw.h
b/drivers/net/wireless/ath/ath10k/hw.h
index 35a3623..59a9a58 100644
--- a/drivers/net/wireless/ath/ath10k/hw.h
+++ b/drivers/net/wireless/ath/ath10k/hw.h
@@ -813,7 +813,7 @@ ath10k_is_rssi_enable(struct ath10k_hw_params *hw,

#define TARGET_10_4_TX_DBG_LOG_SIZE 1024
#define TARGET_10_4_NUM_WDS_ENTRIES 32
-#define TARGET_10_4_DMA_BURST_SIZE 0
+#define TARGET_10_4_DMA_BURST_SIZE 1
#define TARGET_10_4_MAC_AGGR_DELIM 0
#define TARGET_10_4_RX_SKIP_DEFRAG_TIMEOUT_DUP_DETECTION_CHECK 1
#define TARGET_10_4_VOW_CONFIG 0
--
2.7.4

2019-12-19 13:05:42

by Kalle Valo

Subject: Re: [PATCH, v3] Revert "ath10k: fix DMA related firmware crashes on multiple devices"

Zhi Chen <[email protected]> wrote:

> This reverts commit 76d164f582150fd0259ec0fcbc485470bcd8033e.
> PCIe hung issue was observed on multiple platforms. The issue was
> reproduced
> when DUT was configured as AP and associated with 50+ STAs.
>
> For QCA9984/QCA9888, the DMA_BURST_SIZE register controls the AXI burst
> size
> of the RD/WR access to the HOST MEM.
> 0 - No split , RAW read/write transfer size from MAC is put out on bus
> as burst length
> 1 - Split at 256 byte boundary
> 2,3 - Reserved
>
> With PCIe protocol analyzer, we can see DMA Read crossing 4KB boundary
> when
> issue happened. It broke PCIe spec and caused PCIe stuck. So revert
> the default value from 0 to 1.
>
> Tested: IPQ8064 + QCA9984 with firmware 10.4-3.10-00047
> QCS404 + QCA9984 with firmware 10.4-3.9.0.2--00044
> Synaptics AS370 + QCA9888 with firmware 10.4-3.9.0.2--00040
>
> Signed-off-by: Zhi Chen <[email protected]>

Fails to apply:

error: patch failed: drivers/net/wireless/ath/ath10k/hw.h:813
error: drivers/net/wireless/ath/ath10k/hw.h: patch does not apply
stg import: Diff does not apply cleanly

Patch set to Changes Requested.

--
https://patchwork.kernel.org/patch/11287143/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches