Hi Kalle, On Sat, Apr 21, 2018 at 2:10 AM, Kalle Valo <kvalo@xxxxxxxxxxxxxx> wrote: > Jared Bents <jared.bents@xxxxxxxxxxxxxxxxxxx> writes: > >> Update to convert the use of kmemdup to dma_alloc_coherent as >> dma_alloc_coherent will consider DMA region limits such as >> those seen with CONFIG_FSL_PCI && CONFIG_ZONE_DMA32 whereas >> kmemdup does not take those limitations into account. >> >> Signed-off-by: Jared Bents <jared.bents@xxxxxxxxxxxxxxxxxxx> > > Does this fix a real bug or is it just a theoretical issue you noticed > while looking at the code? If this fixes a real bug please give a > description of it. It fixes a real bug that I have experienced. My processor is a qoriq T1042 powerpc and I am running the fsl-sdk-v2.0-1703 kernel (mainline v4.1.35-rt41). In 32 bit, the ath10k and ath9k work without issue. After migrating to 64 bit, we experienced dma mapping errors with both devices. This patch is the only one that applies to a driver, the rest of the updates performed to fix the dma mapping issues deal with the sk_buffs are handled in skbuff, mac80211, and netlink. We worked with NXP to resolve the issue and I believe they will be handling the ones that don't apply to the ath10k driver through their process. If we don't see them after a while, we will be sending them to the kernel as well. Here is the output from the dma mapping problem: ath10k_pci 0000:01:00.0: unable to get target info from device ath10k_pci 0000:01:00.0: could not get target info (-5) ath10k_pci 0000:01:00.0: could not probe fw (-5) > > https://wireless.wiki.kernel.org/en/users/drivers/ath10k/submittingpatches#guidelines > > -- > Kalle Valo Jared Bents
