Hello Mani, On Wed, Jan 10, 2024 at 08:41:37AM +0530, Manivannan Sadhasivam wrote: > On Tue, Jan 09, 2024 at 05:58:53PM +0000, Niklas Cassel wrote: > > On Sun, Jan 07, 2024 at 04:27:07PM +0900, Krzysztof Wilczyński wrote: > > > > Considering that we know that this series introduces new problems > > for drivers with a .core_init_notifier (i.e. tegra and qcom), see: > > https://lore.kernel.org/linux-pci/ZWYmX8Y%2F7Q9WMxES@x1-carbon/ > > > > Do we really want to apply this series as is? > > > > > > Niklas, I think I explained it in this thread itself. Let me reiterate here > again. > > The fact that you are seeing the dmaengine warnings is due to function drivers > not releasing the channels properly. It is not the job of the DWC driver to > release the channels. The channels are requested by the function drivers [1] > and they _should_ release them when the channels are no longer required. Sure, the function driver should release the channels. > > I know that the PCI_EPF_TEST driver is not doing so and so you are seeing the > warnings. But I do not have a device to test that function driver. Qcom > platforms use a dedicated function driver and that releases the channels when it > gets the LINK_DOWN event from EPC [2]. > > So my conclusion is that the issue is there even without this series. If you > still want me to fix the EPF_TEST driver, I can submit a change, but someone has > to test it. That conclusion is not fully correct. Let's take e.g. these error messages that this series introduces: [ 1000.714355] debugfs: File 'mf' in directory '/' already present! [ 1000.714890] debugfs: File 'wr_ch_cnt' in directory '/' already present! [ 1000.715476] debugfs: File 'rd_ch_cnt' in directory '/' already present! [ 1000.716061] debugfs: Directory 'registers' with parent '/' already present! These come from dw_edma_core_debugfs_on(), which is called by dw_edma_probe(). This is a direct result from your patch: https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git/commit/?h=controller/dwc-ep&id=9ab5c8bb7a305135b1b6c65cb8db92b4acbef79d Which moves dw_pcie_edma_detect() from dw_pcie_ep_init_complete() to dw_pcie_ep_late_init() (since dw_pcie_edma_detect() calls dw_edma_probe()). So without your patch, those debugfs error messages are not seen. Thus, I do not think that it is sufficient to only modify the pci-epf-test driver to release the dma channels, as I don't see how that will avoid e.g. the debugfs error messages introduced by this patch. Kind regards, Niklas
