Messages in this thread | | | Subject | Re: [PATCH v6] i2c: virtio: add a virtio i2c frontend driver | From | Jason Wang <> | Date | Wed, 10 Mar 2021 11:59:09 +0800 |
| |
On 2021/3/10 10:22 上午, Jie Deng wrote: > > On 2021/3/4 17:15, Jason Wang wrote: >> >> >>> + } >>> + >>> + if (msgs[i].flags & I2C_M_RD) >>> + memcpy(msgs[i].buf, req->buf, msgs[i].len); >> >> >> Sorry if I had asked this before but any rason not to use msg[i].buf >> directly? >> >> > The msg[i].buf is passed by the I2C core. I just noticed that these > bufs are not > always allocated by kmalloc. They may come from the stack, which may > cause > the check "sg_init_one -> sg_set_buf -> virt_addr_valid" to fail. > Therefore the > msg[i].buf is not suitable for direct use here. > > Regards.
Right, stack is virtually mapped.
Thanks
| |