Re: FAILED: patch "[PATCH] iio: adc: stm32-dfsdm: fix device used to request dma" failed to apply to 5.4-stable tree

[Sasha Levin <sashal@kernel.org>]

On Mon, May 25, 2020 at 03:54:00PM +0200, gregkh@linuxfoundation.org wrote:
>
>The patch below does not apply to the 5.4-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@vger.kernel.org>.
>
>thanks,
>
>greg k-h
>
>------------------ original commit in Linus's tree ------------------
>
>From b455d06e6fb3c035711e8aab1ca18082ccb15d87 Mon Sep 17 00:00:00 2001
>From: Fabrice Gasnier <fabrice.gasnier@st.com>
>Date: Thu, 30 Apr 2020 11:28:46 +0200
>Subject: [PATCH] iio: adc: stm32-dfsdm: fix device used to request dma
>
>DMA channel request should use device struct from platform device struct.
>Currently it's using iio device struct. But at this stage when probing,
>device struct isn't yet registered (e.g. device_register is done in
>iio_device_register). Since commit 71723a96b8b1 ("dmaengine: Create
>symlinks between DMA channels and slaves"), a warning message is printed
>as the links in sysfs can't be created, due to device isn't yet registered:
>- Cannot create DMA slave symlink
>- Cannot create DMA dma:rx symlink
>
>Fix this by using device struct from platform device to request dma chan.
>
>Fixes: eca949800d2d ("IIO: ADC: add stm32 DFSDM support for PDM microphone")
>
>Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
>Cc: <Stable@vger.kernel.org>
>Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

I've also grabbed a9ab624edd91 ("iio: adc: stm32-dfsdm: Use
dma_request_chan() instead dma_request_slave_channel()") and queued both
for 5.4 and 4.19.

-- 
Thanks,
Sasha