Messages in this thread | | | Subject | Re: [PATCH] i2c: ismt: fix wrong device address when unmap the data buffer | From | Peter Rosin <> | Date | Mon, 12 Jun 2017 12:19:48 +0200 |
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On 2017-06-12 11:38, Andy Shevchenko wrote: > On Mon, Jun 12, 2017 at 12:28 PM, Peter Rosin <peda@axentia.se> wrote: >> On 2017-06-12 11:11, Andy Shevchenko wrote: >>> On Mon, Jun 12, 2017 at 6:42 AM, Song liwei <liwei.song@windriver.com> wrote: >>>> From: Liwei Song <liwei.song@windriver.com> > >>>> 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
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