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charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Nov 03, Maxime Chevallier wrote: > The Multi-MSI interrupt handler doesn't clear the DMA error interrupts, > and this leads to interrupt storms when one of these interrupts starts > firing : >=20 > - The RBU (rx buff unav) which triggers under high traffic load >=20 > This triggers easily with iperf3 and small udp packets, and shows > when running the netpoll kselftest >=20 > - The RPS (rx process stop) which triggers when we stop the DMA RX. >=20 > This one shows when restarting the RX logic without doing a down/up > cycle, like when attaching an XDP program. The XSK kselftests > triggers it. >=20 > Let's make sure we clear these interrupts for multi-MSI cases, and call > stmmac_global_err() upon tx_hard_error to avoid possible races with > other interrupts/napi. >=20 > For that introduce an "ERR" DMA dir, as we don't want to touch the > RI/TI bits when handling these interrupts. >=20 > Both of the above storms have been found on dwmac-motorcomm (YT6801), > and are triggered by the xdp.py, xsk_reconfig.py, xdp_features.py, > ring_reconfig.py and netpoll_basic kernel selftests. >=20 > This seems to only affect dwmac4, there's no multi-msi mode on > dwmac1000, and on dwxgmac these interrupts are masked as of today. >=20 > Fixes: 6ccf12ae111e ("net: stmmac: use interrupt mode INTM=3D1 for multi-= MSI") > Signed-off-by: Maxime Chevallier > --- > V2: > - Dropped reviews/tested tags as the implementation has substantially > changed, sorry :( > - Discarded the helper, call directly stmmac_dma_interrupt_status on > all chans and use stmmac_global_err() for TX hard errors, following > sashiko's review. >=20 > drivers/net/ethernet/stmicro/stmmac/common.h | 1 + > .../net/ethernet/stmicro/stmmac/dwmac4_dma.h | 5 +++++ > .../net/ethernet/stmicro/stmmac/dwmac4_lib.c | 2 ++ > .../net/ethernet/stmicro/stmmac/stmmac_main.c | 19 +++++++++++++++++++ > 4 files changed, 27 insertions(+) >=20 > diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/e= thernet/stmicro/stmmac/common.h > index c74bc7c9750e..a972bee66504 100644 > --- a/drivers/net/ethernet/stmicro/stmmac/common.h > +++ b/drivers/net/ethernet/stmicro/stmmac/common.h > @@ -382,6 +382,7 @@ enum dma_irq_dir { > DMA_DIR_RX =3D 0x1, > DMA_DIR_TX =3D 0x2, > DMA_DIR_RXTX =3D 0x3, > + DMA_DIR_ERR =3D 0x4, > }; > =20 > enum request_irq_err { > diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.h b/drivers/n= et/ethernet/stmicro/stmmac/dwmac4_dma.h > index 43b036d4e95b..a7caac3c98e6 100644 > --- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.h > +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.h > @@ -173,6 +173,11 @@ static inline u32 dma_chanx_base_addr(const struct d= wmac4_addrs *addrs, > DMA_CHAN_STATUS_TI | \ > DMA_CHAN_STATUS_MSK_COMMON) > =20 > +#define DMA_CHAN_STATUS_MSK_ERR (DMA_CHAN_STATUS_AIS | \ > + DMA_CHAN_STATUS_FBE | \ > + DMA_CHAN_STATUS_RPS | \ > + DMA_CHAN_STATUS_RBU) > + > int dwmac4_dma_reset(void __iomem *ioaddr); > void dwmac4_enable_dma_irq(struct stmmac_priv *priv, void __iomem *ioadd= r, > u32 chan, bool rx, bool tx); > diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_lib.c b/drivers/n= et/ethernet/stmicro/stmmac/dwmac4_lib.c > index a0249715fafa..02aa1a3dd1e2 100644 > --- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_lib.c > +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_lib.c > @@ -150,6 +150,8 @@ int dwmac4_dma_interrupt(struct stmmac_priv *priv, vo= id __iomem *ioaddr, > intr_status &=3D DMA_CHAN_STATUS_MSK_RX; > else if (dir =3D=3D DMA_DIR_TX) > intr_status &=3D DMA_CHAN_STATUS_MSK_TX; > + else if (dir =3D=3D DMA_DIR_ERR) > + intr_status &=3D DMA_CHAN_STATUS_MSK_ERR; > =20 > /* ABNORMAL interrupts */ > if (unlikely(intr_status & DMA_CHAN_STATUS_AIS)) { > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/= net/ethernet/stmicro/stmmac/stmmac_main.c > index 7ffed295eb14..6360605ef5ea 100644 > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > @@ -3145,6 +3145,22 @@ static int stmmac_napi_check(struct stmmac_priv *p= riv, u32 chan, u32 dir) > return status; > } > =20 > +static void stmmac_dma_err_interrupt(struct stmmac_priv *priv) > +{ > + u8 channels_to_check =3D max(priv->plat->rx_queues_to_use, > + priv->plat->tx_queues_to_use); > + int status; > + u8 chan; > + > + for (chan =3D 0; chan < channels_to_check; chan++) { > + status =3D stmmac_dma_interrupt_status(priv, priv->ioaddr, > + &priv->xstats, chan, > + DMA_DIR_ERR); > + if (unlikely(status & tx_hard_error)) > + stmmac_global_err(priv); > + } > +} > + > /** > * stmmac_dma_interrupt - DMA ISR > * @priv: driver private structure > @@ -6494,6 +6510,9 @@ static irqreturn_t stmmac_mac_interrupt(int irq, vo= id *dev_id) > /* To handle Common interrupts */ > stmmac_common_interrupt(priv); > =20 > + if (priv->plat->core_type =3D=3D DWMAC_CORE_GMAC4) > + stmmac_dma_err_interrupt(priv); > + > return IRQ_HANDLED; > } Reviewed-by: Lorenzo Bianconi > =20 > --=20 > 2.56.0 >=20 --VCchJjwU/KronfNG Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTquNwa3Txd3rGGn7Y6cBh0uS2trAUCaunkiwAKCRA6cBh0uS2t rGlyAP9/4lNlgiouhiFLBiFnn00p1XBEQmgCE2YDorFQ6N0/GgD/WxuwNcrXlVbI Kpjv1IOByUWMenAa0cv2atKZQJ1IKgg= =mOzg -----END PGP SIGNATURE----- --VCchJjwU/KronfNG--