Dear Timur Tabi,
In message 4A8FEA69.9080408@freescale.com you wrote:
Configuring for MVBC_P board... e1000.c: In function 'e1000_transmit': e1000.c:5019: warning: passing argument 1 of 'virt_to_phys' discards qualifiers from pointer target type
I can't reproduce this problem.
...
$ ${CROSS_COMPILE}gcc --version powerpc-linux-gnu-gcc (Sourcery G++ Lite 4.3-74) 4.3.2
I used ELDK 4.2 (gcc-4.2.2).
If you look at the definition of virt_to_bus, you'll see that I added a pointer cast specifically to address this warning:
Well, are you aware how this simple statement gets expanded by the preprocessor?
Out of
txp->buffer_addr = cpu_to_le64(virt_to_bus(hw->pdev, packet));
becomes:
txp->buffer_addr = (__builtin_constant_p((__u64)((pci_hose_phys_to_bus(pci_bus_to_hose(((((hw->pdev)) >> 16) & 0xff)), (virt_to_phys(((void *) (packet)))), (0x00000000))))) ? ((__u64)( (__u64)(((__u64)(((pci_hose_phys_to_bus(pci_bus_to_hose(((((hw->pdev)) >> 16) & 0xff)), (virt_to_phys(((void *) (packet)))), (0x00000000))))) & (__u64)0x00000000000000ffULL) << 56) | (__u64)(((__u64)(((pci_hose_phys_to_bus(pci_bus_to_hose(((((hw->pdev)) >> 16) & 0xff)), (virt_to_phys(((void *) (packet)))), (0x00000000))))) & (__u64)0x000000000000ff00ULL) << 40) | (__u64)(((__u64)(((pci_hose_phys_to_bus(pci_bus_to_hose(((((hw->pdev)) >> 16) & 0xff)), (virt_to_phys(((void *) (packet)))), (0x00000000))))) & (__u64)0x0000000000ff0000ULL) << 24) | (__u64)(((__u64)(((pci_hose_phys_to_bus(pci_bus_to_hose(((((hw->pdev)) >> 16) & 0xff)), (virt_to_phys(((void *) (packet)))), (0x00000000))))) & (__u64)0x00000000ff000000ULL) << 8) | (__u64)(((__u64)(((pci_hose_phys_to_bus(pci_bus_to_hose(((((hw->pdev)) >> 16) & 0xff)), (virt_to_phys(((void *) (packet)))), (0x00000000))))) & (__u64)0x000000ff00000000ULL) >> 8) | (__u64)(((__u64)(((pci_hose_phys_to_bus(pci_bus_to_hose(((((hw->pdev)) >> 16) & 0xff)), (virt_to_phys(((void *) (packet)))), (0x00000000))))) & (__u64)0x0000ff0000000000ULL) >> 24) | (__u64)(((__u64)(((pci_hose_phys_to_bus(pci_bus_to_hose(((((hw->pdev)) >> 16) & 0xff)), (virt_to_phys(((void *) (packet)))), (0x00000000))))) & (__u64)0x00ff000000000000ULL) >> 40) | (__u64)(((__u64)(((pci_hose_phys_to_bus(pci_bus_to_hose(((((hw->pdev)) >> 16) & 0xff)), (virt_to_phys(((void *) (packet)))), (0x00000000))))) & (__u64)0xff00000000000000ULL) >> 56) )) : __fswab64(((pci_hose_phys_to_bus(pci_bus_to_hose(((((hw->pdev)) >> 16) & 0xff)), (virt_to_phys(((void *) (packet)))), (0x00000000))))));
I take my hat off to you if you manage to understand the consequences and results of all this casting going on here.
#define virt_to_bus(devno, v) pci_virt_to_mem(devno, (void *) (v))
Also, I have to admit that I really dislike such casts as they just suppress compiler warnings which are usually valuable - I'd rather see you fixing the original problem (i. e. the type incompatibilities).
If I remove the (void *) cast, I get this:
e1000.c: In function 'e1000_transmit': e1000.c:5019: warning: passing argument 1 of 'virt_to_phys' discards qualifiers from pointer target type
So somehow, you're compiler is ignoring the "(void *)".
I would not go so far to say it is ignoring it. Let's say this cast is insufficient (or simply the wrong approach) to silence the compiler.
Best regards,
Wolfgang Denk