> From: Hillf Danton <hdanton@xxxxxxxx>
> Sent: Saturday, March 18, 2023 11:01 AM
>
> On 14 Mar 2023 10:18:15 +0800 Chia-Wei Wang
> <chiawei_wang@xxxxxxxxxxxxxx>
> > +static irqreturn_t ast2600_udma_isr(int irq, void *arg) {
>
> [...]
>
> > + /* handle RX interrupt */
> > + sts = readl(udma->regs + UDMA_RX_INT_STS);
> > + for_each_set_bit(ch_bit, (unsigned long *)&sts, udma->n_ucs / 2) {
> > + ch_id = (ch_bit << 1) + 1;
> > + wptr = readl(udma->regs + UDMA_CH_WPTR(ch_id));
> > +
> > + uc = &udma->ucs[ch_id];
> > + ud = &uc->ud;
> > + tx = &ud->tx;
> > +
> > + uc->residue = (ud->size & ~UDMA_CH_CTRL_BUFSZ) - wptr;
> > +
> > + /* handle non-4B-aligned case */
> > + if (ud->addr & 0x3) {
> > + p = phys_to_virt(dma_to_phys(uc->chan.device->dev,
> ud->addr));
>
> This does not work if the dma address has no corresponding struct page.
Will add the error check for dma_to_phys to prevent further unexpected memory accesses.
Thanks,
Chiawei
>
> > + memcpy(p, uc->buf, wptr);
> > + }
> > +
> > + ast2600_udma_terminate(&uc->chan);
> > +
> > + dma_cookie_complete(tx);
> > + dma_descriptor_unmap(tx);
> > + dmaengine_desc_get_callback_invoke(tx, NULL);
> > + }
> > +
> > + return IRQ_HANDLED;
> > +}
