On 6/5/2025 6:17 PM, Johan Hovold wrote: > On Thu, Jun 05, 2025 at 12:01:29PM +0800, Miaoqing Pan wrote: >> On 6/5/2025 12:24 AM, Jeff Johnson wrote: >>> On 6/3/2025 7:34 PM, Miaoqing Pan wrote: >>>> We previously had extensive discussions on this topic in the >>>> https://lore.kernel.org/linux-wireless/ecfe850c-b263-4bee-b888-c34178e690fc@xxxxxxxxxxx/ >>>> thread. On my platform, dma_rmb() did not work as expected. The issue >>>> only disappeared after disabling PCIe endpoint relaxed ordering in >>>> firmware side. So it seems that HP was updated (Memory write) before >>>> descriptor (Memory write), which led to the problem. >>> >>> Have all ath11k and ath12k firmware been updated to prevent this problem from >>> the firmware side? >>> >> No, as this is not a widespread issue, and addressing it would require >> modifying the core underlying modules of the firmware. Therefore, we >> chose not to proceed with that approach but instead used the workaround >> patch I previously submitted. If firmware has a concern, how about doing it in host? As I know it is only a register in PCI config space? > > I strongly suggest you fix this at the firmware level rather than try to > work around it in the kernel to avoid playing whack-a-mole whenever a > new (hard to track down) bug shows up. > > The barriers should be enough, but if they are not then the firmware > must be fixed. > > Johan
