On 2017-06-12 11:38, Andy Shevchenko wrote: > On Mon, Jun 12, 2017 at 12:28 PM, Peter Rosin <peda@xxxxxxxxxx> wrote: >> On 2017-06-12 11:11, Andy Shevchenko wrote: >>> On Mon, Jun 12, 2017 at 6:42 AM, Song liwei <liwei.song@xxxxxxxxxxxxx> wrote: >>>> From: Liwei Song <liwei.song@xxxxxxxxxxxxx> > >>>> After finished I2C block read/write, when unmap the data buffer, >>>> a wrong device address was pass to dma_unmap_single(), > >>>> the right >>>> device address should be "dev" not "&adap->dev", the relation is >>>> *(&adap->dev) == dev. >>> >>> This is confusing. You are telling that there are two copies of struct >>> device here? >> >> Yes, there are two copies. > > No, there is not. See below. What I meant was that there are the struct device in pci_dev->dev and the struct device in adap->dev. That seems like two copies of struct device to me. I didn't mean that they are copies in the sense that they have the same content, but in the sense that they are both struct device. I guess we can argue ourselves blue over this point. > There are two struct devices, Hmm, two struct devices, I seem to recall that from somewhere... :-) > one is a real PCI device, which > represents actual device what *does* DMA. > This struct should be used according to DMA API. When you put it like that, it's obvious that the patch is correct. I had this feeling that little thought had gone into the choice to pick "dev" over "&adap->dev", that's all. > Another struct device which is wrongly used is an artificial one that > represents I2C adapter in terms of Linux kernel. Cheers, peda -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
