On 21-01-30 15:51:49, David Rientjes wrote: > On Fri, 29 Jan 2021, Ben Widawsky wrote: > > > +static int cxl_mem_setup_mailbox(struct cxl_mem *cxlm) > > +{ > > + const int cap = cxl_read_mbox_reg32(cxlm, CXLDEV_MB_CAPS_OFFSET); > > + > > + cxlm->mbox.payload_size = > > + 1 << CXL_GET_FIELD(cap, CXLDEV_MB_CAP_PAYLOAD_SIZE); > > + > > + /* 8.2.8.4.3 */ > > + if (cxlm->mbox.payload_size < 256) { > > + dev_err(&cxlm->pdev->dev, "Mailbox is too small (%zub)", > > + cxlm->mbox.payload_size); > > + return -ENXIO; > > + } > > Any reason not to check cxlm->mbox.payload_size > (1 << 20) as well and > return ENXIO if true? If some crazy vendor wanted to ship a mailbox larger than 1M, why should the driver not allow it? I'm open to changing it, it just seems like a larger mailbox wouldn't be fatal.