On Mon, 2020-09-14 at 12:28 +1000, Nicholas Piggin wrote:
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Excerpts from Chris Packham's message of September 14, 2020 8:03 am:
Hi All,
On 4/09/20 12:28 pm, Chris Packham wrote:
The SPIE register contains counts for the TX FIFO so any time the irq handler was invoked we would attempt to process the RX/TX fifos. Use the SPIM value to mask the events so that we only process interrupts that were expected.
This was a latent issue exposed by commit 3282a3da25bd ("powerpc/64: Implement soft interrupt replay in C").
Signed-off-by: Chris Packham chris.packham@alliedtelesis.co.nz Cc: stable@vger.kernel.org
ping?
I don't know the code/hardware but thanks for tracking this down.
Was there anything more to be done with Jocke's observations, or would that be a follow-up patch if anything?
Patch is good IMHO, there may be more to fix w.r.t clearing the IRQs
If this patch fixes your problem it should probably go in, unless there are any objections.
It should go in I think.
Jocke
Thanks, Nick
Notes: I've tested this on a T2080RDB and a custom board using the T2081 SoC. With this change I don't see any spurious instances of the "Transfer done but SPIE_DON isn't set!" or "Transfer done but rx/tx fifo's aren't empty!" messages and the updates to spi flash are successful.
I think this should go into the stable trees that contain 3282a3da25bd but I haven't added a Fixes: tag because I think 3282a3da25bd exposed the issue as opposed to causing it.
drivers/spi/spi-fsl-espi.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/spi/spi-fsl-espi.c b/drivers/spi/spi-fsl-espi.c index 7e7c92cafdbb..cb120b68c0e2 100644 --- a/drivers/spi/spi-fsl-espi.c +++ b/drivers/spi/spi-fsl-espi.c @@ -574,13 +574,14 @@ static void fsl_espi_cpu_irq(struct fsl_espi *espi, u32 events) static irqreturn_t fsl_espi_irq(s32 irq, void *context_data) { struct fsl_espi *espi = context_data;
- u32 events;
- u32 events, mask;
spin_lock(&espi->lock);
/* Get interrupt events(tx/rx) */ events = fsl_espi_read_reg(espi, ESPI_SPIE);
- if (!events) {
- mask = fsl_espi_read_reg(espi, ESPI_SPIM);
- if (!(events & mask)) {
spin_unlock(&espi->lock); return IRQ_NONE; }