Hello Bjorn, >> >> On Mon, Nov 25, 2013 at 07:03:11PM +0000, Rajat Jain wrote: >> > Hello, >> > >> > > > On a different note, I feel there is still a need to apply my >> > > > original >> > > patch. There is still an open problem in case of spurious interrupts >> > > (or in any case where the condition "if (slot_status & >> PCI_EXP_SLTSTA_CC)" >> > > becomes true in pcie_write_cmd()). That is because once that >> > > happens, we never clear that interrupt, and no further hotplug >> > > interrupts shall be received unless we do that. >> > > >> > > I agree this is an issue and we should address it somehow. My >> > > hesitation is just that I'd prefer to do some more aggressive >> > > restructuring rather than apply a point fix. For example: >> > >> > OK, I'll attempt to fix it that way when I get time. >> > >> > > >> > > - We currently look at PCI_EXP_SLTSTA_CC in pcie_isr(), >> > > pcie_poll_cmd(), and pcie_write_cmd(). I think it would be better >> > > to look at it only in pcie_isr(). >> > > >> > > - I don't think pcie_poll_cmd() should exist at all; we should poll >> > > by calling pcie_isr() instead. >> > > >> > > - We need pcie_write_cmd(), but I think the way it waits is >> backwards. >> > > Currently we issue the command, then wait for it to complete. I >> > > think we should issue the command, note the current time, and return >> > > without waiting. The *next* time we need to issue a command, we can >> > > wait for completion of the previous one (or timeout) if necessary. >> > > >> > > But maybe we need the point fix in the interim, especially if >> > > anybody can actually produce the scenario you mention. >> > >> > Ok. >> >> This patch is still in patchwork, but I've lost track of where we are. >> Did you resolve this in the series that I just applied, or is it still >> an outstanding issue? > > No, I did not solve it. It is still an outstanding issue. So far I am using your patch to overcome this: > > http://www.spinics.net/lists/hotplug/msg05830.html > > I'll just attempt to conclude the status on this issue so that you can make the decision on the course of action. IMHO there are 2 independent issues that we discussed in this thread: > > 1) PCIe compliant HW (that generates cmd completed interrupts at every write of Slot_ctrl register) being penalized with 1 second delay during the boot up. Your patch solves this. > > 2) If there is a genuine spurious interrupt, it does not get acknowledged. I had originally posted a patch for THIS problem. > http://www.spinics.net/lists/hotplug/msg05815.html > > You had indicated that you would rather want a bigger restructuring of the driver to solve (2). > > My observation: MY problem (in my setup) is not seen if I use either of the patches (yours or mine). > > My opinion: I think my patch solves (2) but might not solve (1) for all corner cases. Also your patch solves (1) but may not solve (2) for all corner cases -Thus we should probably solve both of these problems individually. > Just wondering if you decided on how to solve this problem? Are you planning this for 3.15? Thanks, Rajat -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
