Re: [dpdk-dev] [v4] net/e1000: i219 unit hang issue fix on reset/close

["Zhang, Xiao" <xiao.zhang@intel.com>]

Hi Anand,

Sorry, I didn't get your last email.

Thanks,
Xiao

> -----Original Message-----
> From: Anand H. Krishnan [mailto:anandhkrishnan@gmail.com]
> Sent: Tuesday, July 16, 2019 9:03 AM
> To: Zhang, Xiao <xiao.zhang@intel.com>
> Cc: dev@dpdk.org; Zhao1, Wei <wei.zhao1@intel.com>
> Subject: Re: [v4] net/e1000: i219 unit hang issue fix on reset/close
> 
> Xiao,
> 
> I didn't hear back from you on the comments.
> 
> Thanks,
> Anand
> 
> On Wed, Jul 10, 2019 at 10:18 AM Anand H. Krishnan
> <anandhkrishnan@gmail.com> wrote:
> >
> > More comments inline:
> >
> > On Tue, Jul 9, 2019 at 9:16 PM Xiao Zhang <xiao.zhang@intel.com> wrote:
> > >
> > > Unit hang may occur if multiple descriptors are available in the
> > > rings during reset or close. This state can be detected by configure
> > > status by bit 8 in register. If the bit is set and there are pending
> > > descriptors in one of the rings, we must flush them before reset or close.
> > >
> > > Signed-off-by: Xiao Zhang <xiao.zhang@intel.com>
> > > ---
> > >  drivers/net/e1000/e1000_ethdev.h |   4 ++
> > >  drivers/net/e1000/igb_ethdev.c   |   4 ++
> > >  drivers/net/e1000/igb_rxtx.c     | 105
> +++++++++++++++++++++++++++++++++++++++
> > >  3 files changed, 113 insertions(+)
> > >
> > > diff --git a/drivers/net/e1000/e1000_ethdev.h
> > > b/drivers/net/e1000/e1000_ethdev.h
> > > index 67acb73..349144a 100644
> > > --- a/drivers/net/e1000/e1000_ethdev.h
> > > +++ b/drivers/net/e1000/e1000_ethdev.h
> > > @@ -35,6 +35,9 @@
> > >  #define IGB_MAX_RX_QUEUE_NUM           8
> > >  #define IGB_MAX_RX_QUEUE_NUM_82576     16
> > >
> > > +#define E1000_I219_MAX_RX_QUEUE_NUM            2
> > > +#define E1000_I219_MAX_TX_QUEUE_NUM            2
> > > +
> > >  #define E1000_SYN_FILTER_ENABLE        0x00000001 /* syn filter enable
> field */
> > >  #define E1000_SYN_FILTER_QUEUE         0x0000000E /* syn filter queue
> field */
> > >  #define E1000_SYN_FILTER_QUEUE_SHIFT   1          /* syn filter queue field
> */
> > > @@ -522,5 +525,6 @@ int igb_action_rss_same(const struct
> > > rte_flow_action_rss *comp,  int igb_config_rss_filter(struct rte_eth_dev
> *dev,
> > >                         struct igb_rte_flow_rss_conf *conf,
> > >                         bool add);
> > > +void igb_flush_desc_rings(struct rte_eth_dev *dev);
> > >
> > >  #endif /* _E1000_ETHDEV_H_ */
> > > diff --git a/drivers/net/e1000/igb_ethdev.c
> > > b/drivers/net/e1000/igb_ethdev.c index 3ee28cf..845101b 100644
> > > --- a/drivers/net/e1000/igb_ethdev.c
> > > +++ b/drivers/net/e1000/igb_ethdev.c
> > > @@ -1589,6 +1589,10 @@ eth_igb_close(struct rte_eth_dev *dev)
> > >         eth_igb_stop(dev);
> > >         adapter->stopped = 1;
> > >
> > > +       /* Flush desc rings for i219 */
> > > +       if (hw->mac.type >= e1000_pch_spt)
> > > +               igb_flush_desc_rings(dev);
> > > +
> >
> > I am a bit confused as to which driver handles i219. I thought it is
> > the em_ethdev.c.
> > Also, the place to put this code, I think is more appropriate in eth_em_stop.

Yes, I checked with the card, it used em_ethdev driver and adding this code in stop ops will be better.

> >
> >
> > >         e1000_phy_hw_reset(hw);
> > >         igb_release_manageability(hw);
> > >         igb_hw_control_release(hw);
> > > diff --git a/drivers/net/e1000/igb_rxtx.c
> > > b/drivers/net/e1000/igb_rxtx.c index c5606de..cad28f3 100644
> > > --- a/drivers/net/e1000/igb_rxtx.c
> > > +++ b/drivers/net/e1000/igb_rxtx.c
> > > @@ -18,6 +18,7 @@
> > >  #include <rte_log.h>
> > >  #include <rte_debug.h>
> > >  #include <rte_pci.h>
> > > +#include <rte_bus_pci.h>
> > >  #include <rte_memory.h>
> > >  #include <rte_memcpy.h>
> > >  #include <rte_memzone.h>
> > > @@ -63,6 +64,10 @@
> > >  #define IGB_TX_OFFLOAD_NOTSUP_MASK \
> > >                 (PKT_TX_OFFLOAD_MASK ^ IGB_TX_OFFLOAD_MASK)
> > >
> > > +/* PCI offset for querying descriptor ring status*/
> > > +#define PCICFG_DESC_RING_STATUS           0xE4
> > > +#define FLUSH_DESC_REQUIRED               0x100
> > > +
> > >  /**
> > >   * Structure associated with each descriptor of the RX ring of a RX queue.
> > >   */
> > > @@ -2962,3 +2967,103 @@ igb_config_rss_filter(struct rte_eth_dev
> > > *dev,
> > >
> > >         return 0;
> > >  }
> > > +
> > > +static void e1000_flush_tx_ring(struct rte_eth_dev *dev) {
> > > +       struct e1000_hw *hw = E1000_DEV_PRIVATE_TO_HW(dev->data-
> >dev_private);
> > > +       volatile union e1000_adv_tx_desc *tx_desc;
> > > +       uint32_t tdt, tctl, txd_lower = E1000_TXD_CMD_IFCS;
> > > +       uint16_t size = 512;
> > > +       struct igb_tx_queue *txq;
> > > +       int i;
> > > +
> > > +       if (dev->data->tx_queues == NULL)
> > > +               return;
> > > +       tctl = E1000_READ_REG(hw, E1000_TCTL);
> > > +       E1000_WRITE_REG(hw, E1000_TCTL, tctl | E1000_TCTL_EN);
> > > +       for (i = 0; i < dev->data->nb_tx_queues &&
> > > +               i < E1000_I219_MAX_TX_QUEUE_NUM; i++) {
> > > +               txq = dev->data->tx_queues[i];
> > > +               tdt = E1000_READ_REG(hw, E1000_TDT(i));
> > > +               if (tdt != txq->tx_tail)
> > > +                       return;
> > > +               tx_desc = &txq->tx_ring[txq->tx_tail];
> > > +               tx_desc->read.buffer_addr = txq->tx_ring_phys_addr;
> >
> > Should you be using rte_cpu_to_le64 here?

Will add conversion for this field.

> >
> >
> > > +               tx_desc->read.cmd_type_len =
> > > + rte_cpu_to_le_32(txd_lower | size);
> >
> > There is a lower.data  and upper.data that needs to be set, not this
> > field AFAIR.

As I checked the kernel driver, in the struct e1000_tx_desc, the lower and upper data are cmd/length and status.

> >
> >
> > > +               tx_desc->read.olinfo_status = 0;
> > > +
> > > +               rte_wmb();
> > > +               txq->tx_tail++;
> > > +               if (txq->tx_tail == txq->nb_tx_desc)
> > > +                       txq->tx_tail = 0;
> > > +               rte_io_wmb();
> > > +               E1000_WRITE_REG(hw, E1000_TDT(i), txq->tx_tail);
> >
> > Should you be using E1000_PCI_REG_WRITE_RELAXED. Can you just check
> > other instances of how this register is written?

Will use E1000_PCI_REG_WRITE_RELAXED to write register.

> >
> > Thanks,
> > Anand
> >
> >
> > > +               usec_delay(250);
> > > +       }
> > > +}
> > > +
> > > +static void e1000_flush_rx_ring(struct rte_eth_dev *dev) {
> > > +       uint32_t rctl, rxdctl;
> > > +       struct e1000_hw *hw = E1000_DEV_PRIVATE_TO_HW(dev->data-
> >dev_private);
> > > +       int i;
> > > +
> > > +       rctl = E1000_READ_REG(hw, E1000_RCTL);
> > > +       E1000_WRITE_REG(hw, E1000_RCTL, rctl & ~E1000_RCTL_EN);
> > > +       E1000_WRITE_FLUSH(hw);
> > > +       usec_delay(150);
> > > +
> > > +       for (i = 0; i < dev->data->nb_rx_queues &&
> > > +               i < E1000_I219_MAX_RX_QUEUE_NUM; i++) {
> > > +               rxdctl = E1000_READ_REG(hw, E1000_RXDCTL(i));
> > > +               /* zero the lower 14 bits (prefetch and host thresholds) */
> > > +               rxdctl &= 0xffffc000;
> > > +
> > > +               /* update thresholds: prefetch threshold to 31,
> > > +                * host threshold to 1 and make sure the granularity
> > > +                * is "descriptors" and not "cache lines"
> > > +                */
> > > +               rxdctl |= (0x1F | (1UL << 8) |
> > > + E1000_RXDCTL_THRESH_UNIT_DESC);
> > > +
> > > +               E1000_WRITE_REG(hw, E1000_RXDCTL(i), rxdctl);
> > > +       }
> > > +       /* momentarily enable the RX ring for the changes to take effect */
> > > +       E1000_WRITE_REG(hw, E1000_RCTL, rctl | E1000_RCTL_EN);
> > > +       E1000_WRITE_FLUSH(hw);
> > > +       usec_delay(150);
> > > +       E1000_WRITE_REG(hw, E1000_RCTL, rctl & ~E1000_RCTL_EN); }
> > > +
> > > +/**
> > > + * igb_flush_desc_rings - remove all descriptors from the
> > > +descriptor rings
> > > + *
> > > + * In i219, the descriptor rings must be emptied before
> > > +resetting/closing the
> > > + * HW. Failure to do this will cause the HW to enter a unit hang
> > > +state which
> > > + * can only be released by PCI reset on the device
> > > + *
> > > + */
> > > +
> > > +void igb_flush_desc_rings(struct rte_eth_dev *dev) {
> > > +       uint32_t fextnvm11, tdlen;
> > > +       struct e1000_hw *hw = E1000_DEV_PRIVATE_TO_HW(dev->data-
> >dev_private);
> > > +       struct rte_pci_device *pci_dev = RTE_ETH_DEV_TO_PCI(dev);
> > > +       uint32_t hang_state = 0;
> > > +
> > > +       fextnvm11 = E1000_READ_REG(hw, E1000_FEXTNVM11);
> > > +       E1000_WRITE_REG(hw, E1000_FEXTNVM11,
> > > +                       fextnvm11 | E1000_FEXTNVM11_DISABLE_MULR_FIX);
> > > +       tdlen = E1000_READ_REG(hw, E1000_TDLEN(0));
> > > +       rte_pci_read_config(pci_dev, &hang_state, sizeof(hang_state),
> > > +                               PCICFG_DESC_RING_STATUS);
> > > +
> > > +       /* do nothing if we're not in faulty state, or if the queue is empty */
> > > +       if ((hang_state & FLUSH_DESC_REQUIRED) && tdlen) {
> > > +               /* flush desc ring */
> > > +               e1000_flush_tx_ring(dev);
> > > +               rte_pci_read_config(pci_dev, &hang_state, sizeof(hang_state),
> > > +                                       PCICFG_DESC_RING_STATUS);
> > > +               if (hang_state & FLUSH_DESC_REQUIRED)
> > > +                       e1000_flush_rx_ring(dev);
> > > +       }
> > > +}
> > > --
> > > 2.7.4
> > >