On 7/4/2019 2:45 AM, Leonard Crestez wrote: > On 7/3/2019 8:14 PM, Andrey Smirnov wrote: >> On Wed, Jul 3, 2019 at 6:51 AM Leonard Crestez <leonard.crestez@xxxxxxx> wrote: >>> On 7/3/2019 11:14 AM, Andrey Smirnov wrote: >>>> Move tasklet_init() call further down in order to simplify error path >>>> cleanup. No functional change intended. >>>> >>>> diff --git a/drivers/crypto/caam/jr.c b/drivers/crypto/caam/jr.c >>>> index 4b25b2fa3d02..a7ca2bbe243f 100644 >>>> --- a/drivers/crypto/caam/jr.c >>>> +++ b/drivers/crypto/caam/jr.c >>>> @@ -441,15 +441,13 @@ static int caam_jr_init(struct device *dev) >>>> >>>> jrp = dev_get_drvdata(dev); >>>> >>>> - tasklet_init(&jrp->irqtask, caam_jr_dequeue, (unsigned long)dev); >>>> - >>>> /* Connect job ring interrupt handler. */ >>>> error = request_irq(jrp->irq, caam_jr_interrupt, IRQF_SHARED, >>>> dev_name(dev), dev); >>>> if (error) { >>>> dev_err(dev, "can't connect JobR %d interrupt (%d)\n", >>>> jrp->ridx, jrp->irq); >>>> - goto out_kill_deq; >>>> + return error; >>>> } >>> >>> The caam_jr_interrupt handler can schedule the tasklet so it makes sense >>> to have it be initialized ahead of request_irq. In theory it's possible >>> for an interrupt to be triggered immediately when request_irq is called. >>> >>> I'm not very familiar with the CAAM ip, can you ensure no interrupts are >>> pending in HW at probe time? The "no functional change" part is not obvious. >>> Actually there is a previous report (in i.MX BSP) of CAAM job ring generating an interrupt at probe time, between request_irq() and reset: https://source.codeaurora.org/external/imx/linux-imx/commit/drivers/crypto/caam?h=imx_4.14.98_2.0.0_ga&id=aa7b3f51971ec1f60f41fe8ea71870b215376b8a So yes, there might be cases when interrupts are pending. >> >> Said tasklet will use both jrp->outring and jrp->entinfo array >> initialized after IRQ request call in both versions of the code >> (before/after this patch). AFAICT, the only case where this patch >> would change initialization safety of the original code is if JR was >> scheduled somehow while ORSFx is 0 (no jobs done), which I don't think >> is possible. > > I took a second look at caam_jr_init and there is apparently a whole > bunch of other reset/init stuff done after request_irq. For example > caam_reset_hw_jr is done after request_irq and masks interrupts? > > What I'd expect is that request_irq is done last after all other > initialization is performed. But I'm not familiar with how CAAM JRs work > so feel free to ignore this. > There's some history here... (which is in contradiction with above-mentioned report). Commit 9620fd959fb1 ("crypto: caam - handle interrupt lines shared across rings") moved request_irq() before JR reset: " - resetting a job ring triggers an interrupt, so move request_irq prior to jr_reset to avoid 'got IRQ but nobody cared' messages. " but IIUC that ("resetting a job ring triggers an interrupt") was actually due to disabling the IRQ line using disable_irq() instead of masking the interrupt in HW using JRCFGR_LS[IMSK]. The way JR reset sequence is implemented now - in caam_reset_hw_jr() - should not trigger any interrupt. Thus, it should be safe to move request_irq() after everything is set up, at the end of probing. My suggestion is to move both tasklet_init() and request_irq() at the bottom of the probe callback. However, I'd say this is a fix that should be marked accordingly and should be posted either separately, or at the top of the patch set. Thanks, Horia