Hi Lorenzo, Gustavo, On Wed, 26 Sep 2018 21:31:36 +0900 <hayashi.kunihiko@xxxxxxxxxxxxx> wrote: > Hi Lorenzo, Gustavo, > > Thank you for reviewing. > > On Tue, 25 Sep 2018 18:53:01 +0100 > Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx> wrote: > > > On 25/09/2018 17:14, Lorenzo Pieralisi wrote: > > > [+Gustavo, please have a look at INTX/MSI management] > > > > > > On Thu, Sep 06, 2018 at 06:40:32PM +0900, Kunihiko Hayashi wrote: > > >> This introduces specific glue layer for UniPhier platform to support > > >> PCIe host controller that is based on the DesignWare PCIe core, and > > >> this driver supports Root Complex (host) mode. > > > > > > Please read this thread and apply it to next versions: > > > > > > https://urldefense.proofpoint.com/v2/url?u=https-3A__marc.info_-3Fl-3Dlinux-2Dpci-26m-3D150905742808166-26w-3D2&d=DwIBAg&c=DPL6_X_6JkXFx7AXWqB0tg&r=bkWxpLoW-f-E3EdiDCCa0_h0PicsViasSlvIpzZvPxs&m=H8UNDDUGQnQnqfWr4CBios689dJcjxu4qeTTRGulLmU&s=CgcXc_2LThyOpW-4bCriJNo9H1lzROEdy_cG9p-Y5hU&e= > > I also found this thread in previous linux-pci, and I think it's helpful for me. > I'll check it carefully. [snip] > > >> + ret = devm_request_irq(dev, pp->irq, uniphier_pcie_irq_handler, > > >> + IRQF_SHARED, "pcie", priv); > > > > > > This is wrong, you should set-up a chained IRQ for INTX. > > > > > > I *think* that > > > > > > ks_pcie_setup_interrupts() > > > > > > is a good example to start with but I wonder whether it is worth > > > generalizing the INTX approach to designware as a whole as it was > > > done for MSIs. > > > > > > Thoughts ? > > > > From what I understood this is for legacy IRQ, right? > > Yes. For legacy IRQ. > > > Like you (Lorenzo) said there is 2 drivers (pci-keystone-dw.c and pci-dra7xx.c) > > that uses it and can be use as a template for handling this type of interrupts. > > > > We can try to pass some kind of generic INTX function to the DesignWare host > > library to handling this, but this will require some help from keystone and > > dra7xx maintainers, since my setup doesn't have legacy IRQ HW support. > > Now I think it's difficult to make a template for INTX function, > and at first, I'll try to re-write this part with reference to pci-keystone-dw.c. I understand that there are 2 types of interrupt and the drivers. One like pci-keystone-dw.c is: - there are 4 interrupts for legacy, - invoke handlers for each interrupt, and handle the interrupt, - call irq_set_chained_handler_and_data() to make a chain of the interrupts when initializing The other like pci-dra7xx.c is: - there is 1 IRQ for legacy as a parent, - check an interrupt factor register, and handle the interrupt correspond to the factor, - call request_irq() for the parent IRQ and irq_domain_add_linear() for the factor when initializing The pcie-uniphier.c is the same type as the latter (like pci-dra7xx.c). However, in pci-dra7xx.c, MSI and legacy IRQ share the same interrupt number, so the same handler is called and the handler divides these IRQs. (found in dra7xx_pcie_msi_irq_handler()) In pcie-uniphier.c, MSI and legacy IRQ are independent. Therefore it's necessary to prepare the handler for the legacy IRQ. I think that it's difficult to apply the way of pci-keystone-dw.c, and uniphier_pcie_irq_handler() and calling devm_request_irq() are still necessary to handle legacy IRQ. Thank you, --- Best Regards, Kunihiko Hayashi
