On 21/04/07 04:37PM, Leon Romanovsky wrote: > On Wed, Apr 07, 2021 at 06:36:01PM +0530, ameynarkhed...@gmail.com wrote: > > On 21/04/07 03:30PM, Leon Romanovsky wrote: > > > On Wed, Apr 07, 2021 at 01:53:56PM +0530, ameynarkhed...@gmail.com wrote: > > > > On 21/04/07 10:23AM, Leon Romanovsky wrote: > > > > > On Tue, Apr 06, 2021 at 08:16:26AM -0600, Alex Williamson wrote: > > > > > > On Sun, 4 Apr 2021 11:04:32 +0300 > > > > > > Leon Romanovsky <l...@kernel.org> wrote: > > > > > > > > > > > > > On Thu, Apr 01, 2021 at 10:56:16AM -0600, Alex Williamson wrote: > > > > > > > > On Thu, 1 Apr 2021 15:27:37 +0300 > > > > > > > > Leon Romanovsky <l...@kernel.org> wrote: > > > > > > > > > > > > > > > > > On Thu, Apr 01, 2021 at 05:37:16AM +0000, Raphael Norwitz > > > > > > > > > wrote: > > > > > > > > > > Slot resets are bus resets with additional logic to prevent > > > > > > > > > > a device > > > > > > > > > > from being removed during the reset. Currently slot and bus > > > > > > > > > > resets have > > > > > > > > > > separate implementations in pci.c, complicating higher > > > > > > > > > > level logic. As > > > > > > > > > > discussed on the mailing list, they should be combined into > > > > > > > > > > a generic > > > > > > > > > > function which performs an SBR. This change adds a function, > > > > > > > > > > pci_reset_bus_function(), which first attempts a slot reset > > > > > > > > > > and then > > > > > > > > > > attempts a bus reset if -ENOTTY is returned, such that > > > > > > > > > > there is now a > > > > > > > > > > single device agnostic function to perform an SBR. > > > > > > > > > > > > > > > > > > > > This new function is also needed to add SBR reset quirks > > > > > > > > > > and therefore > > > > > > > > > > is exposed in pci.h. > > > > > > > > > > > > > > > > > > > > Link: https://lkml.org/lkml/2021/3/23/911 > > > > > > > > > > > > > > > > > > > > Suggested-by: Alex Williamson <alex.william...@redhat.com> > > > > > > > > > > Signed-off-by: Amey Narkhede <ameynarkhed...@gmail.com> > > > > > > > > > > Signed-off-by: Raphael Norwitz <raphael.norw...@nutanix.com> > > > > > > > > > > --- > > > > > > > > > > drivers/pci/pci.c | 17 +++++++++-------- > > > > > > > > > > include/linux/pci.h | 1 + > > > > > > > > > > 2 files changed, 10 insertions(+), 8 deletions(-) > > > > > > > > > > > > > > > > > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > > > > > > > > index 16a17215f633..12a91af2ade4 100644 > > > > > > > > > > --- a/drivers/pci/pci.c > > > > > > > > > > +++ b/drivers/pci/pci.c > > > > > > > > > > @@ -4982,6 +4982,13 @@ static int > > > > > > > > > > pci_dev_reset_slot_function(struct pci_dev *dev, int probe) > > > > > > > > > > return pci_reset_hotplug_slot(dev->slot->hotplug, > > > > > > > > > > probe); > > > > > > > > > > } > > > > > > > > > > > > > > > > > > > > +int pci_reset_bus_function(struct pci_dev *dev, int probe) > > > > > > > > > > +{ > > > > > > > > > > + int rc = pci_dev_reset_slot_function(dev, probe); > > > > > > > > > > + > > > > > > > > > > + return (rc == -ENOTTY) ? pci_parent_bus_reset(dev, > > > > > > > > > > probe) : rc; > > > > > > > > > > > > > > > > > > The previous coding style is preferable one in the Linux > > > > > > > > > kernel. > > > > > > > > > int rc = pci_dev_reset_slot_function(dev, probe); > > > > > > > > > if (rc != -ENOTTY) > > > > > > > > > return rc; > > > > > > > > > return pci_parent_bus_reset(dev, probe); > > > > > > > > > > > > > > > > > > > > > > > > That'd be news to me, do you have a reference? I've never seen > > > > > > > > complaints for ternaries previously. Thanks, > > > > > > > > > > > > > > The complaint is not to ternaries, but to the function call as > > > > > > > one of > > > > > > > the parameters, that makes it harder to read. > > > > > > > > > > > > Sorry, I don't find a function call as a parameter to a ternary to > > > > > > be > > > > > > extraordinary, nor do I find it to be a discouraged usage model > > > > > > within > > > > > > the kernel. This seems like a pretty low bar for hard to read code. > > > > > > > > > > It is up to us where this bar is set. > > > > > > > > > > Thanks > > > > On the side note there are plenty of places where this pattern is used > > > > though > > > > for example - > > > > kernel/time/clockevents.c:328: > > > > return force ? clockevents_program_min_delta(dev) : -ETIME; > > > > > > > > kernel/trace/trace_kprobe.c:233: > > > > return tk ? within_error_injection_list(trace_kprobe_address(tk)) : > > > > false; > > > > > > > > kernel/signal.c:3104: > > > > return oset ? put_compat_sigset(oset, &old_set, sizeof(*oset)) : 0; > > > > etc > > > > > > Did you look when they were introduced? > > > > > > Thanks > > > > > that code trace_kprobe in 2 years old. > > If you want more recent example checkout > > drivers/pci/controller/pcie-brcmstb.c:1112,1117: > > return pcie->rescal ? brcm_phy_cntl(pcie, 1) : 0; > > which was introduced 7 months ago. > > There are lot of examples in pci.c also. > > Yeah, I know, copy-paste is a powerful tool. > > Can we please progress with this patch instead of doing > archaeological research? > > Thanks > Sorry I didn't understand what you said.
Thanks, Amey