Messages in this thread | | | From | Ezequiel Garcia <> | Date | Tue, 30 Jul 2019 11:17:39 -0300 | Subject | Re: [PATCH net] net: stmmac: Sync RX Buffer upon allocation |
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On Tue, 30 Jul 2019 at 10:57, Jose Abreu <Jose.Abreu@synopsys.com> wrote: > > With recent changes that introduced support for Page Pool in stmmac, Jon > reported that NFS boot was no longer working on an ARM64 based platform > that had the IP behind an IOMMU. > > As Page Pool API does not guarantee DMA syncing because of the use of > DMA_ATTR_SKIP_CPU_SYNC flag, we have to explicit sync the whole buffer upon > re-allocation because we are always re-using same pages. > > In fact, ARM64 code invalidates the DMA area upon two situations [1]: > - sync_single_for_cpu(): Invalidates if direction != DMA_TO_DEVICE > - sync_single_for_device(): Invalidates if direction == DMA_FROM_DEVICE > > So, as we must invalidate both the current RX buffer and the newly allocated > buffer we propose this fix. > > [1] arch/arm64/mm/cache.S > > Reported-by: Jon Hunter <jonathanh@nvidia.com> > Tested-by: Jon Hunter <jonathanh@nvidia.com> > Fixes: 2af6106ae949 ("net: stmmac: Introducing support for Page Pool") > Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Thanks a lot for the bug hunt and the fix. This fixes NFS mounting on my RK3288 and RK3399 boards.
Tested-by: Ezequiel Garcia <ezequiel@collabora.com>
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