On Mon, Aug 01, 2022 at 02:27:14PM -0600, Rob Herring wrote: > On Sat, Jul 30, 2022 at 8:50 AM Manivannan Sadhasivam > <manivannan.sadhasivam@xxxxxxxxxx> wrote: > > > > On Fri, Jul 29, 2022 at 05:44:04PM -0500, Bjorn Helgaas wrote: > > > [+cc Xiaowei (author of 6bfc9c3a2c70), Hou (author of 8bcca2658558)] > > > > > > On Thu, Jul 28, 2022 at 05:56:28PM +0530, Vidya Sagar wrote: > > > > On 7/28/2022 3:44 AM, Bjorn Helgaas wrote: > > > > > On Wed, Jun 22, 2022 at 09:31:33AM +0530, Vidya Sagar wrote: > > > > > > Platforms that cannot support their core initialization without the > > > > > > reference clock from the host, implement the feature 'core_init_notifier' > > > > > > to indicate the DesignWare sub-system about when their core is getting > > > > > > initialized. Any accesses to the core (Ex:- DBI) would result in system > > > > > > hang in such systems (Ex:- tegra194). This patch moves any access to the > > > > > > core to dw_pcie_ep_init_complete() API which is effectively called only > > > > > > after the core initialization. > > > > 6) What's going on with the CORE_INIT and LINK_UP notifiers? > > > dw_pcie_ep_init_notify() is only called by qcom and tegra. > > > dw_pcie_ep_linkup() is only called by dra7xx, qcom, and tegra. > > > As far as I can tell, nobody at all registers to handle those > > > events except a test. I think it's pointless to have that code > > > if nobody uses it. > > > > > > > I have submitted an actual driver that makes use of these notifiers: > > https://lore.kernel.org/lkml/20220502060611.58987-9-manivannan.sadhasivam@xxxxxxxxxx/ > > Notifiers aren't the best interface in the kernel. I think they are > best used if there's no real linkage between the sender and receiver. > For an EPC and EPF that's a fixed interface, so define a proper > interface. > Fair point! The use of notifiers also suffer from an issue where the notifier chain in EPC is atomic but the EPF calls some of the functions like pci_epc_write_header() could potentially sleep. I'll try to come up with an interface. Thanks, Mani > Rob -- மணிவண்ணன் சதாசிவம்
