Hi Geert,
Thanks for your feedback.
On 2018-08-31 00:10:28 +0200, Geert Uytterhoeven wrote:
> Hi Niklas,
>
> Thanks for your patch!
>
> On Thu, Aug 30, 2018 at 11:39 PM Niklas Söderlund
> <niklas.soderlund+renesas@xxxxxxxxxxxx> wrote:
> > Fix warning when running with CONFIG_DMA_API_DEBUG_SG=y by allocating a
> > device_dma_parameters structure and filling in the max segment size. The
> > size used is the result of a discussion with Renesas hardware engineers
> > and unfortunately not found in the datasheet.
> >
> > renesas_sdhi_internal_dmac ee140000.sd: DMA-API: mapping sg segment
> > longer than device claims to support [len=126976] [max=65536A]
>
> Bogus trailing "A".
Thanks, that is a odd copy-and-past error :-)
>
> > Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
> > Reported-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> >
> > ---
> >
> > * Changes since v1
> > - Use devm_kzalloc() instead of a custom remove function to clean up.
> > ---
> > drivers/mmc/host/renesas_sdhi_internal_dmac.c | 11 +++++++++++
> > 1 file changed, 11 insertions(+)
> >
> > diff --git a/drivers/mmc/host/renesas_sdhi_internal_dmac.c b/drivers/mmc/host/renesas_sdhi_internal_dmac.c
> > index c9dab9ce1ed55174..715e0c5dc30e4ebf 100644
> > --- a/drivers/mmc/host/renesas_sdhi_internal_dmac.c
> > +++ b/drivers/mmc/host/renesas_sdhi_internal_dmac.c
> > @@ -308,12 +308,23 @@ static const struct soc_device_attribute gen3_soc_whitelist[] = {
> > static int renesas_sdhi_internal_dmac_probe(struct platform_device *pdev)
> > {
> > const struct soc_device_attribute *soc = soc_device_match(gen3_soc_whitelist);
> > + struct device *dev = &pdev->dev;
> >
> > if (!soc)
> > return -ENODEV;
> >
> > global_flags |= (unsigned long)soc->data;
> >
> > + if (!dev->dma_parms) {
>
> I guess dev->dma_parms is retained on unbind/rebind?
>
> > + dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms),
> > + GFP_KERNEL);
>
> But by using devm_kzalloc(), the memory will be freed, and lead to reuse after
> free?
I don't know how the unbind/rebind behaves in this regard. In v1 of this
patch I used kzalloc() and a remove function to free the memory and
reset the dev->dma_parms pointe to NULL. Do you think that is the
correct approach here?
>
> > + if (!dev->dma_parms)
> > + return -ENOMEM;
> > + }
> > +
> > + if (dma_set_max_seg_size(dev, 0xffffffff))
> > + dev_warn(dev, "Unable to set seg size\n");
> > +
> > return renesas_sdhi_probe(pdev, &renesas_sdhi_internal_dmac_dma_ops);
> > }
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
--
Regards,
Niklas Söderlund
