Messages in this thread | | | Subject | Re: [PATCH 1/4 net] qca_spi: Fix SPI thread creation | From | Paolo Abeni <> | Date | Thu, 23 Nov 2023 12:26:53 +0100 |
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On Tue, 2023-11-21 at 17:30 +0100, Stefan Wahren wrote: > The qca_spi driver create/stop the SPI kernel thread in case > of netdev_open/close. This is a big issue because it allows > userspace to prevent from restarting the SPI thread after > ring parameter changes (e.g. signals which stop the thread). > This could be done by terminating a script which changes > the ring parameter in a loop. > > So fix this by moving create/stop of the SPI kernel into > the init/uninit ops. The open/close ops could be realized just > by 'park/unpark' the SPI kernel thread. > > Fixes: 291ab06ecf67 ("net: qualcomm: new Ethernet over SPI driver for QCA7000") > Signed-off-by: Stefan Wahren <wahrenst@gmx.net> > --- > drivers/net/ethernet/qualcomm/qca_spi.c | 35 ++++++++++++++++--------- > 1 file changed, 23 insertions(+), 12 deletions(-) > > diff --git a/drivers/net/ethernet/qualcomm/qca_spi.c b/drivers/net/ethernet/qualcomm/qca_spi.c > index bec723028e96..b11a998b2456 100644 > --- a/drivers/net/ethernet/qualcomm/qca_spi.c > +++ b/drivers/net/ethernet/qualcomm/qca_spi.c > @@ -580,6 +580,11 @@ qcaspi_spi_thread(void *data) > netdev_info(qca->net_dev, "SPI thread created\n"); > while (!kthread_should_stop()) { > set_current_state(TASK_INTERRUPTIBLE); > + if (kthread_should_park()) { > + kthread_parkme(); > + continue; > + } > + > if ((qca->intr_req == qca->intr_svc) && > !qca->txr.skb[qca->txr.head]) > schedule(); > @@ -679,25 +684,17 @@ qcaspi_netdev_open(struct net_device *dev) > qca->sync = QCASPI_SYNC_UNKNOWN; > qcafrm_fsm_init_spi(&qca->frm_handle); > > - qca->spi_thread = kthread_run((void *)qcaspi_spi_thread, > - qca, "%s", dev->name); > - > - if (IS_ERR(qca->spi_thread)) { > - netdev_err(dev, "%s: unable to start kernel thread.\n", > - QCASPI_DRV_NAME); > - return PTR_ERR(qca->spi_thread); > - } > - > ret = request_irq(qca->spi_dev->irq, qcaspi_intr_handler, 0, > dev->name, qca); > if (ret) { > netdev_err(dev, "%s: unable to get IRQ %d (irqval=%d).\n", > QCASPI_DRV_NAME, qca->spi_dev->irq, ret); > - kthread_stop(qca->spi_thread); > return ret; > } > > /* SPI thread takes care of TX queue */ > + kthread_unpark(qca->spi_thread); > + wake_up_process(qca->spi_thread);
The above looks racy: after 'request_irq()' the interrupt handler can raise an irq before the thread being unparked.
Additionally I think you can drop the 'if (qca->spi_thread)' in qcaspi_intr_handler()
Cheers,
Paolo
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