On Mon, Oct 14, 2019 at 05:58:16PM +0200, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From dcb10920179ab74caf88a6f2afadecfc2743b910 Mon Sep 17 00:00:00 2001
From: Fabrice Gasnier <fabrice.gasnier@xxxxxx>
Date: Tue, 17 Sep 2019 14:38:16 +0200
Subject: [PATCH] iio: adc: stm32-adc: fix a race when using several adcs with
dma and irq
End of conversion may be handled by using IRQ or DMA. There may be a
race when two conversions complete at the same time on several ADCs.
EOC can be read as 'set' for several ADCs, with:
- an ADC configured to use IRQs. EOCIE bit is set. The handler is normally
called in this case.
- an ADC configured to use DMA. EOCIE bit isn't set. EOC triggers the DMA
request instead. It's then automatically cleared by DMA read. But the
handler gets called due to status bit is temporarily set (IRQ triggered
by the other ADC).
So both EOC status bit in CSR and EOCIE control bit must be checked
before invoking the interrupt handler (e.g. call ISR only for
IRQ-enabled ADCs).
Fixes: 2763ea0585c9 ("iio: adc: stm32: add optional dma support")
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx>
Cc: <Stable@xxxxxxxxxxxxxxx>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
It would be nice if a stable patch wouldn't depend on a massive code
movement patch...
Anyway, I ported both to 4.19 as it was just a minor missing dependency,
but 4.14 requires more work I'll leave to someone who knows that code
better than me.
--
Thanks,
Sasha
