Re: [dpdk-dev] [PATCH v3 1/3] bus/pci: enable PCI master in command register

["Wang, Haiyue" <haiyue.wang@intel.com>]

> -----Original Message-----
> From: David Marchand <david.marchand@redhat.com>
> Sent: Tuesday, April 27, 2021 17:29
> To: Wang, Haiyue <haiyue.wang@intel.com>; Gaetan Rivet <grive@u256.net>
> Cc: dev <dev@dpdk.org>; Zhang, Qi Z <qi.z.zhang@intel.com>; Wang, Liang-min <liang-min.wang@intel.com>;
> Ray Kinsella <mdr@ashroe.eu>; Neil Horman <nhorman@tuxdriver.com>
> Subject: Re: [dpdk-dev] [PATCH v3 1/3] bus/pci: enable PCI master in command register
> 
> On Fri, Apr 23, 2021 at 2:06 PM Haiyue Wang <haiyue.wang@intel.com> wrote:
> > diff --git a/drivers/bus/pci/rte_bus_pci.h b/drivers/bus/pci/rte_bus_pci.h
> > index 64886b473..83caf477b 100644
> > --- a/drivers/bus/pci/rte_bus_pci.h
> > +++ b/drivers/bus/pci/rte_bus_pci.h
> > @@ -249,6 +249,18 @@ void rte_pci_dump(FILE *f);
> >  __rte_experimental
> >  off_t rte_pci_find_ext_capability(struct rte_pci_device *dev, uint32_t cap);
> >
> > +/**
> > + * Enables Bus Master for device's PCI command register.
> > + *
> > + *  @param dev
> > + *    A pointer to rte_pci_device structure.
> > + *
> > + *  @return
> > + *  0 on success, -1 on error in PCI config space read/write.
> > + */
> > +__rte_experimental
> > +int rte_pci_enable_bus_master(struct rte_pci_device *dev);
> 
> I can see pci/vfio and net/hns3 has a similar helper to enable *and*
> disable bus master.
> 
> I'd rather go with a "set" helper, and then we can clean existing
> drivers who had their own helper:
> drivers/bus/pci/linux/pci_uio.c
> drivers/bus/pci/linux/pci_vfio.c
> drivers/net/hns3/hns3_ethdev_vf.c
> 
> 

Got it, will change it to 'set'.

> > +
> >  /**
> >   * Register a PCI driver.
> >   *
> > diff --git a/drivers/bus/pci/version.map b/drivers/bus/pci/version.map
> > index f33ed0abd..9dbec12a0 100644
> > --- a/drivers/bus/pci/version.map
> > +++ b/drivers/bus/pci/version.map
> > @@ -21,4 +21,7 @@ EXPERIMENTAL {
> >         global:
> >
> >         rte_pci_find_ext_capability;
> > +
> > +       # added in 21.05
> > +       rte_pci_enable_bus_master;
> >  };
> > diff --git a/lib/pci/rte_pci.h b/lib/pci/rte_pci.h
> > index a8f8e404a..1f33d687f 100644
> > --- a/lib/pci/rte_pci.h
> > +++ b/lib/pci/rte_pci.h
> > @@ -32,6 +32,10 @@ extern "C" {
> >
> >  #define RTE_PCI_VENDOR_ID      0x00    /* 16 bits */
> >  #define RTE_PCI_DEVICE_ID      0x02    /* 16 bits */
> > +#define RTE_PCI_COMMAND                0x04    /* 16 bits */
> 
> This file uses tab for indent.
> 

Yes, I use two tabs, then the vi editor shows that they are aligned.
but the patch doesn't show well.

So use one tab ?

> 
> > +
> > +/* PCI Command Register */
> > +#define RTE_PCI_COMMAND_MASTER 0x4     /* Bus Master Enable */
> >
> >  /* PCI Express capability registers */
> >  #define RTE_PCI_EXP_DEVCTL     8       /* Device Control */
> > --
> > 2.31.1
> >
> 
> 
> --
> David Marchand