Re: [PATCH] soc: fsl: qbman: avoid race in clearing QMan interrupt
From: Li Yang <hidden>
Date: 2019-01-18 22:56:18
Also in:
linux-arm-kernel, linuxppc-dev, lkml
On Fri, Dec 21, 2018 at 8:43 AM Madalin Bucur [off-list ref] wrote:
By clearing all interrupt sources, not only those that already occurred, the existing code may acknowledge by mistake interrupts that occurred after the code checks for them. Signed-off-by: Madalin Bucur <madalin.bucur@nxp.com> Signed-off-by: Roy Pledge <redacted>
Applied for fix. Thanks. Suggest to forward it to stable@vger.kernel.org after merged into Linus' tree. It would be better to add "Cc: stable@vger.kernel.org" in the commit message for similar patches next time. Regards, Leo
quoted hunk ↗ jump to hunk
--- drivers/soc/fsl/qbman/qman.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)diff --git a/drivers/soc/fsl/qbman/qman.c b/drivers/soc/fsl/qbman/qman.c index 52c153cd795a..636f83f781f5 100644 --- a/drivers/soc/fsl/qbman/qman.c +++ b/drivers/soc/fsl/qbman/qman.c@@ -1143,18 +1143,19 @@ static void qm_mr_process_task(struct work_struct *work); static irqreturn_t portal_isr(int irq, void *ptr) { struct qman_portal *p = ptr; - - u32 clear = QM_DQAVAIL_MASK | p->irq_sources; u32 is = qm_in(&p->p, QM_REG_ISR) & p->irq_sources; + u32 clear = 0; if (unlikely(!is)) return IRQ_NONE; /* DQRR-handling if it's interrupt-driven */ - if (is & QM_PIRQ_DQRI) + if (is & QM_PIRQ_DQRI) { __poll_portal_fast(p, QMAN_POLL_LIMIT); + clear = QM_DQAVAIL_MASK | QM_PIRQ_DQRI; + } /* Handling of anything else that's interrupt-driven */ - clear |= __poll_portal_slow(p, is); + clear |= __poll_portal_slow(p, is) & QM_PIRQ_SLOW; qm_out(&p->p, QM_REG_ISR, clear); return IRQ_HANDLED; } --2.1.0