Hi Geert,
Thanks for the feedback.
> Subject: Re: [PATCH] spi: Fix invalid sgs value
>
> Hi Biju,
>
> On Mon, Mar 7, 2022 at 7:01 PM Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> wrote:
> > max_seg_size is unsigned int and it can have a value up to 2^32 (for
> > eg:-RZ_DMAC driver sets dma_set_max_seg_size as U32_MAX) When this
> > value is used in min_t() as an integer type, it becomes
> > -1 and the value of sgs becomes 0.
> >
> > Fix this issue by replacing the 'int' data type with 'unsigned int'
> > in min_t().
> >
> > Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
>
> Thanks for your patch!
>
> > --- a/drivers/spi/spi.c
> > +++ b/drivers/spi/spi.c
> > @@ -1019,10 +1019,10 @@ int spi_map_buf(struct spi_controller *ctlr,
> struct device *dev,
> > int i, ret;
> >
> > if (vmalloced_buf || kmap_buf) {
> > - desc_len = min_t(int, max_seg_size, PAGE_SIZE);
> > + desc_len = min_t(unsigned int, max_seg_size,
> > + PAGE_SIZE);
> > sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
> > } else if (virt_addr_valid(buf)) {
> > - desc_len = min_t(int, max_seg_size, ctlr->max_dma_len);
> > + desc_len = min_t(unsigned int, max_seg_size, (unsigned
> > + int)ctlr->max_dma_len);
>
> The cast of the last parameter is not needed.
OK. I thought since last param is size_t, casting is required.
OK will drop this.
Cheers,
Biju
>
> > sgs = DIV_ROUND_UP(len, desc_len);
> > } else {
> > return -EINVAL;
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-
> m68k.org
>
> 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
