diff options
| author | Sugar Zhang <sugar.zhang@rock-chips.com> | 2019-04-03 19:06:22 +0800 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2019-04-26 16:51:37 +0530 |
| commit | 2da254cc7908105a60a6bb219d18e8dced03dcb9 (patch) | |
| tree | 0d58d112ce9b0c64f73b4f24e0d3b0092891a83c /drivers/dma | |
| parent | 9a05045d2a681d36c80aafc08d9d0b63d4ddbc66 (diff) | |
| download | linux-2da254cc7908105a60a6bb219d18e8dced03dcb9.tar.bz2 | |
dmaengine: pl330: _stop: clear interrupt status
This patch kill instructs the DMAC to immediately terminate
execution of a thread. and then clear the interrupt status,
at last, stop generating interrupts for DMA_SEV. to guarantee
the next dma start is clean. otherwise, one interrupt maybe leave
to next start and make some mistake.
we can reporduce the problem as follows:
DMASEV: modify the event-interrupt resource, and if the INTEN sets
function as interrupt, the DMAC will set irq<event_num> HIGH to
generate interrupt. write INTCLR to clear interrupt.
DMA EXECUTING INSTRUCTS DMA TERMINATE
| |
| |
... _stop
| |
| spin_lock_irqsave
DMASEV |
| |
| mask INTEN
| |
| DMAKILL
| |
| spin_unlock_irqrestore
in above case, a interrupt was left, and if we unmask INTEN, the DMAC
will set irq<event_num> HIGH to generate interrupt.
to fix this, do as follows:
DMA EXECUTING INSTRUCTS DMA TERMINATE
| |
| |
... _stop
| |
| spin_lock_irqsave
DMASEV |
| |
| DMAKILL
| |
| clear INTCLR
| mask INTEN
| |
| spin_unlock_irqrestore
Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma')
| -rw-r--r-- | drivers/dma/pl330.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index c72f6fd79c43..6e6837214210 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -967,6 +967,7 @@ static void _stop(struct pl330_thread *thrd) { void __iomem *regs = thrd->dmac->base; u8 insn[6] = {0, 0, 0, 0, 0, 0}; + u32 inten = readl(regs + INTEN); if (_state(thrd) == PL330_STATE_FAULT_COMPLETING) UNTIL(thrd, PL330_STATE_FAULTING | PL330_STATE_KILLING); @@ -979,10 +980,13 @@ static void _stop(struct pl330_thread *thrd) _emit_KILL(0, insn); - /* Stop generating interrupts for SEV */ - writel(readl(regs + INTEN) & ~(1 << thrd->ev), regs + INTEN); - _execute_DBGINSN(thrd, insn, is_manager(thrd)); + + /* clear the event */ + if (inten & (1 << thrd->ev)) + writel(1 << thrd->ev, regs + INTCLR); + /* Stop generating interrupts for SEV */ + writel(inten & ~(1 << thrd->ev), regs + INTEN); } /* Start doing req 'idx' of thread 'thrd' */ |