Re: [PATCH] iio: amplifiers: ada4250: use DMA-safe memory for regmap_bulk_read()

Andy Shevchenko
2025-04-19T15:03:17Z

On Fri, Apr 18, 2025 at 02:09:04PM -0500, David Lechner wrote:
> On 4/18/25 1:58 PM, Andy Shevchenko wrote:
> > пʼятниця, 18 квітня 2025 р. David Lechner <dlechner@baylibre.com <mailto:dlechner@baylibre.com>> пише:
> >
> > Use DMA-safe memory instead of stack-allocated memory for the call to
> > regmap_bulk_read() in the ada4250_init() function as this could be used
> > directly by a SPI controller.
> >
> > Sorry, but can you elaborate more on this? If driver doesn’t override the
> > callbacks the regmap SPI uses spi_write_then_read() which is supposed to be
> > dma safe.
>
> Ah, I didn't dig that far down. Will send a new patch that just cleans up the
> unnecessary alignment and unaligned call.

But do you have a real life issue with that? Coincidentally we discussed
similar case in another driver with colleague of mine, and he insists that it
might be still broken (somewhere).

> (Also can't believe you sent HTML mail!)

Yeah, Gmail from the phone can't actually send a plain text :-(
Very strange from Google, while I understand that the case most
likely is for business, where HTML is a standard (sic!) for emails.

--
With Best Regards,
Andy Shevchenko