diff options
| author | Philipp Rosenberger <p.rosenberger@kunbus.com> | 2023-05-09 07:28:56 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2023-05-12 04:00:37 +0300 |
| commit | 995585ecdf42c14fbd4d9d12ca73bf54358581c6 (patch) | |
| tree | d94a545560110ec9d3e9330648e5e5cdf2badd8c /drivers/net/ethernet/microchip/enc28j60.c | |
| parent | bc88ba0cad64a4aa85f9deca79c6f3addcd21795 (diff) | |
| download | linux-995585ecdf42c14fbd4d9d12ca73bf54358581c6.tar.xz | |
net: enc28j60: Use threaded interrupt instead of workqueue
The Microchip ENC28J60 SPI Ethernet driver schedules a work item from
the interrupt handler because accesses to the SPI bus may sleep.
On PREEMPT_RT (which forces interrupt handling into threads) this
old-fashioned approach unnecessarily increases latency because an
interrupt results in first waking the interrupt thread, then scheduling
the work item. So, a double indirection to handle an interrupt.
Avoid by converting the driver to modern threaded interrupt handling.
Signed-off-by: Philipp Rosenberger <p.rosenberger@kunbus.com>
Signed-off-by: Zhi Han <hanzhi09@gmail.com>
[lukas: rewrite commit message, linewrap request_threaded_irq() call]
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Piotr Raczynski <piotr.raczynski@intel.com>
Link: https://lore.kernel.org/r/342380d989ce26bc49f0e5d45fbb0416a5f7809f.1683606193.git.lukas@wunner.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net/ethernet/microchip/enc28j60.c')
| -rw-r--r-- | drivers/net/ethernet/microchip/enc28j60.c | 28 |
1 files changed, 6 insertions, 22 deletions
diff --git a/drivers/net/ethernet/microchip/enc28j60.c b/drivers/net/ethernet/microchip/enc28j60.c index 176efbeae127..d6c9491537e4 100644 --- a/drivers/net/ethernet/microchip/enc28j60.c +++ b/drivers/net/ethernet/microchip/enc28j60.c @@ -58,7 +58,6 @@ struct enc28j60_net { struct mutex lock; struct sk_buff *tx_skb; struct work_struct tx_work; - struct work_struct irq_work; struct work_struct setrx_work; struct work_struct restart_work; u8 bank; /* current register bank selected */ @@ -1118,10 +1117,9 @@ static int enc28j60_rx_interrupt(struct net_device *ndev) return ret; } -static void enc28j60_irq_work_handler(struct work_struct *work) +static irqreturn_t enc28j60_irq(int irq, void *dev_id) { - struct enc28j60_net *priv = - container_of(work, struct enc28j60_net, irq_work); + struct enc28j60_net *priv = dev_id; struct net_device *ndev = priv->netdev; int intflags, loop; @@ -1225,6 +1223,8 @@ static void enc28j60_irq_work_handler(struct work_struct *work) /* re-enable interrupts */ locked_reg_bfset(priv, EIE, EIE_INTIE); + + return IRQ_HANDLED; } /* @@ -1309,22 +1309,6 @@ static void enc28j60_tx_work_handler(struct work_struct *work) enc28j60_hw_tx(priv); } -static irqreturn_t enc28j60_irq(int irq, void *dev_id) -{ - struct enc28j60_net *priv = dev_id; - - /* - * Can't do anything in interrupt context because we need to - * block (spi_sync() is blocking) so fire of the interrupt - * handling workqueue. - * Remember that we access enc28j60 registers through SPI bus - * via spi_sync() call. - */ - schedule_work(&priv->irq_work); - - return IRQ_HANDLED; -} - static void enc28j60_tx_timeout(struct net_device *ndev, unsigned int txqueue) { struct enc28j60_net *priv = netdev_priv(ndev); @@ -1559,7 +1543,6 @@ static int enc28j60_probe(struct spi_device *spi) mutex_init(&priv->lock); INIT_WORK(&priv->tx_work, enc28j60_tx_work_handler); INIT_WORK(&priv->setrx_work, enc28j60_setrx_work_handler); - INIT_WORK(&priv->irq_work, enc28j60_irq_work_handler); INIT_WORK(&priv->restart_work, enc28j60_restart_work_handler); spi_set_drvdata(spi, priv); /* spi to priv reference */ SET_NETDEV_DEV(dev, &spi->dev); @@ -1578,7 +1561,8 @@ static int enc28j60_probe(struct spi_device *spi) /* Board setup must set the relevant edge trigger type; * level triggers won't currently work. */ - ret = request_irq(spi->irq, enc28j60_irq, 0, DRV_NAME, priv); + ret = request_threaded_irq(spi->irq, NULL, enc28j60_irq, IRQF_ONESHOT, + DRV_NAME, priv); if (ret < 0) { if (netif_msg_probe(priv)) dev_err(&spi->dev, "request irq %d failed (ret = %d)\n", |