Hi,

Please can commit a1769bb68a850508a492e3674ab1e5e479b11254 be back merged to the 4.4, 4.9, 4.14, 4.19 and 5.4 LTS kernels to resolve a PCIe hang with Wave 2-generation 802.11ac QCA chips?

commit a1769bb68a850508a492e3674ab1e5e479b11254 author Zhi Chen zhichen@codeaurora.org date 2020-01-14 12:35:21 +0800

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

The issue resolved is that a value of 0 has a different meaning and instruction depending on the specific chip. Wave 1 and Wave 2 QCA 802.11ac chips use this differently.

This meant that the original commit introduced a regression for the Wave 2-generation 802.11ac QCA chips when seeking to resolve a firmware crash issue affecting some Wave 1-generation 802.11ac QCA chips.

This subsequently has only been partially reverted via this commit, specifically for the 10_4 target only via TARGET_10_4_DMA_BURST_SIZE 1

The original commit that caused this regression from back in 2015 is 76d164f582150fd0259ec0fcbc485470bcd8033e

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

With thanks,

Nick