Re: [PATCH] staging: gasket: Fix sparse "incorrect type in assignment" warnings.

[Greg Kroah-Hartman]

On Wed, Oct 10, 2018 at 03:03:05PM +0100, Laurence Rochfort wrote:
> On Tue, Oct 09, 2018 at 03:13:03PM +0200, Greg Kroah-Hartman wrote:
> > On Thu, Oct 04, 2018 at 06:52:25PM +0100, Laurence Rochfort wrote:
> > > Silence the below sparse warnings by casting betwen u8 __iomem *, and
> > > void *.
> > > 
> > > warning: incorrect type in assignment (different address spaces)
> > >    expected unsigned char [noderef] [usertype] <asn:2>*virt_base
> > >    got void *[assigned] mem
> > > warning: incorrect type in argument 3 (different address spaces)
> > >    expected void *cpu_addr
> > >    got unsigned char [noderef] [usertype] <asn:2>*virt_base
> > > 
> > > Signed-off-by: Laurence Rochfort <laurence.rochfort@xxxxxxxxx>
> > > ---
> > >  drivers/staging/gasket/gasket_page_table.c | 10 +++++-----
> > >  1 file changed, 5 insertions(+), 5 deletions(-)
> > > 
> > > diff --git a/drivers/staging/gasket/gasket_page_table.c b/drivers/staging/gasket/gasket_page_table.c
> > > index d4c5f8a..7f5e5b3 100644
> > > --- a/drivers/staging/gasket/gasket_page_table.c
> > > +++ b/drivers/staging/gasket/gasket_page_table.c
> > > @@ -1278,7 +1278,7 @@ int gasket_alloc_coherent_memory(struct gasket_dev *gasket_dev, u64 size,
> > >  				 dma_addr_t *dma_address, u64 index)
> > >  {
> > >  	dma_addr_t handle;
> > > -	void *mem;
> > > +	u8 __iomem *mem;
> > >  	int j;
> > >  	unsigned int num_pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
> > >  	const struct gasket_driver_desc *driver_desc =
> > > @@ -1290,7 +1290,7 @@ int gasket_alloc_coherent_memory(struct gasket_dev *gasket_dev, u64 size,
> > >  	if (num_pages == 0)
> > >  		return -EINVAL;
> > >  
> > > -	mem = dma_alloc_coherent(gasket_get_device(gasket_dev),
> > > +	mem = (u8 __iomem *)dma_alloc_coherent(gasket_get_device(gasket_dev),
> > >  				 num_pages * PAGE_SIZE, &handle, 0);
> > >  	if (!mem)
> > >  		goto nomem;
> > > @@ -1325,7 +1325,7 @@ int gasket_alloc_coherent_memory(struct gasket_dev *gasket_dev, u64 size,
> > >  nomem:
> > >  	if (mem) {
> > >  		dma_free_coherent(gasket_get_device(gasket_dev),
> > > -				  num_pages * PAGE_SIZE, mem, handle);
> > > +				  num_pages * PAGE_SIZE, (void __force *)mem, handle);
> > >  	}
> > >  
> > >  	if (gasket_dev->page_table[index]->coherent_pages) {
> > > @@ -1353,7 +1353,7 @@ int gasket_free_coherent_memory(struct gasket_dev *gasket_dev, u64 size,
> > >  	if (gasket_dev->coherent_buffer.length_bytes) {
> > >  		dma_free_coherent(gasket_get_device(gasket_dev),
> > >  				  gasket_dev->coherent_buffer.length_bytes,
> > > -				  gasket_dev->coherent_buffer.virt_base,
> > > +				  (void __force *)gasket_dev->coherent_buffer.virt_base,
> > 
> > We should not have to "force" anything here.  Something feels wrong in
> > the definition of these variable types...

> >From bde80ff6bdab740d838210aa3e664c8901b2142a Mon Sep 17 00:00:00 2001
> From: Laurence Rochfort <laurence.rochfort@xxxxxxxxx>
> Date: Thu, 4 Oct 2018 18:42:26 +0100
> Subject: [PATCH v2] staging: gasket: Fix sparse "incorrect type in assignment"
>  warnings.
> 
> Correct the coherent buffer data type and memory space cookie.

Why have you attached a patch?  I can't do anything with that.

And it seems wrong as well, are you sure about this change?

greg k-h