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FMC ADC 100M 14b 4cha - Software
Commit 152c819d authored by Federico Vaga's avatar Federico Vaga
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[bug-fix] fa-zio-drv.c: handle interrupt race condition 

There is a little window of time where it happens that the
acquisition_done interrupt come after reading the irq_status but before
the irq acknowledgment. The result is that also acquisition_done is
acked

To solve the problem, the irq handler give the irq acknowledgment only
after it handles all active interrupts. Then, it reads again for active
interrupt and it handles them
Signed-off-by: 's avatarFederico Vaga <federico.vaga@gmail.com>
parent 4d733007
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Showing with 19 additions and 6 deletions
kernel/fa-zio-drv.c
View file @ 152c819d
......@@ -907,22 +907,22 @@ static irqreturn_t zfad_irq(int irq, void *ptr)
struct fa_dev *fa = fmc_get_drvdata(fmc);
struct zio_cset *cset = fa->zdev->cset;
uint32_t status, multi;
int max_try = 10;
/* irq to handle */
zfat_get_irq_status(fa, &status, &multi);
if (!status)
return IRQ_NONE;
/* ack the irq */
fa->fmc->op->irq_ack(fa->fmc);
irq_handler:
dev_dbg(fa->fmc->hwdev, "Handle ADC interrupts\n");
if (unlikely((status & (ZFAT_DMA_DONE | ZFAT_DMA_ERR)) &&
(status & (ZFAT_TRG_FIRE | ZFAT_ACQ_END)))) {
WARN(1, "Cannot handle trigger interrupt and DMA interrupt at "
"the same time\n");
/* Stop Acquisition, ADC it is not working properly */
zfad_fsm_command(fa, ZFA_STOP);
return IRQ_NONE;
return IRQ_HANDLED;
}
/*
* It cannot happen that DMA_DONE is in the multi register.
......@@ -933,7 +933,6 @@ static irqreturn_t zfad_irq(int irq, void *ptr)
}
if (unlikely((status | multi) & ZFAT_DMA_ERR)) {
zfad_dma_error(cset);
return IRQ_HANDLED;
}
/* Fire the trigger for each interrupt */
......@@ -943,11 +942,25 @@ static irqreturn_t zfad_irq(int irq, void *ptr)
zfat_irq_trg_fire(cset);
/*
* If it is too fast the ACQ_END interrupt can be in the
* multi register
* multi register.
*/
if ((status | multi) & ZFAT_ACQ_END)
zfat_irq_acq_end(cset);
/* ack the irq */
fa->fmc->op->irq_ack(fa->fmc);
/*
* Read again the interrupt status. It can happen that an interrupt
* is raised while we was processing a previous interrupt. If there
* are new active interrupts, then handle them.
* This handler cannot monopolize the processor, so it check for
* new interrupts only 'max_try' times.
*/
zfat_get_irq_status(fa, &status, &multi);
if ((status || multi) && --max_try)
goto irq_handler;
return IRQ_HANDLED;
}
......
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