Thread (37 messages) 37 messages, 3 authors, 21d ago

Re: [PATCH v4 10/14] mfd: lm3533: Set DMA mask

From: Svyatoslav Ryhel <hidden>
Date: 2026-06-10 14:41:10
Also in: dri-devel, linux-devicetree, linux-iio, linux-leds, lkml

вт, 9 черв. 2026 р. о 22:17 Andy Shevchenko [off-list ref] пише:
On Sat, Jun 06, 2026 at 07:57:34AM +0300, Svyatoslav Ryhel wrote:
quoted
Missing coherent_dma_mask assigning triggers the following warning in
dmesg:

[    3.287872] platform lm3533-backlight.0: DMA mask not set

Since this warning might be elevated to an error in the future, set
coherent_dma_mask to zero because both the core and cells do not utilize
DMA.
Hmm... I am not sure about this. The entire kernel has only two drivers that
do that, and thanks to their commit messages one of them pointed out to the
commit from 2018. So, if no other devices suffer from this, I think it has to
be a better way of achieving the same.
If mfd framework warns that DMA mask is not set then this must be
addressed. Why then there is such warning at the first place if mask
can be just skipped. Then warning would be just a debug message. What
is warning today can become error tomorrow.
--
With Best Regards,
Andy Shevchenko
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