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drivers/misc: Aspeed LPC control fix compile error and warning

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pgprot_dmachoerent() is not defined on every architecture. Having
COMPILE_TEST set for the driver causes it to be compiled on
architectures which do not have pgprot_dmachoerent():
    drivers/misc/aspeed-lpc-ctrl.c: In function 'aspeed_lpc_ctrl_mmap':
    drivers/misc/aspeed-lpc-ctrl.c:51:9: error: implicit declaration of
        function 'pgprot_dmacoherent' [-Werror=implicit-function-declaration]
        prot = pgprot_dmacoherent(prot);

There are two possible solutions:
    1. Remove COMPILE_TEST to ensure the driver is only compiled on ARM
    2. Use pgprot_noncached() instead of pgprot_dmachoerent()

The first option results in less compile testing of the LPC control
driver which is undesirable.
The second option uses a function that is declared on all architectures
and therefore should always build. Currently there is no practical
difference between pgprot_noncached() and pgprot_dmachoerent() for the
aspeed chips that this driver is compatible with. The reason for
pgprot_dmachoerent() was that there may be chips made at some point in
the future that could include hardware that pgprot_dmachoerent() could
optimise for. As none of this hardware has even been announced there
isn't really a need for pgprot_dmachoerent().

Using pgprot_noncached() is completely correct and optimal for all
existing hardware on which the LPC control driver will run.

This commit also addresses that phys_addr_t should be printed using %pap
rather than %x:
    In file included from include/linux/miscdevice.h:6:0,
                     from drivers/misc/aspeed-lpc-ctrl.c:11:
    drivers/misc/aspeed-lpc-ctrl.c: In function 'aspeed_lpc_ctrl_probe':
    drivers/misc/aspeed-lpc-ctrl.c:232:17: warning: format '%x' expects
        argument of type 'unsigned int', but argument 3 has type 'phys_addr_t
        {aka long long unsigned int}' [-Wformat=]
        dev_info(dev, "Loaded at 0x%08x (0x%08x)\n",

Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Cyril Bur 2017-03-22 14:13:28 +11:00 committed by Greg Kroah-Hartman
parent ac1ddc584e
commit 132c93d421
1 changed files with 3 additions and 3 deletions
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6
drivers/misc/aspeed-lpc-ctrl.c
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@ -48,7 +48,7 @@ static int aspeed_lpc_ctrl_mmap(struct file *file, struct vm_area_struct *vma)
return -EINVAL;
/* ast2400/2500 AHB accesses are not cache coherent */
prot = pgprot_dmacoherent(prot);
prot = pgprot_noncached(prot);
if (remap_pfn_range(vma, vma->vm_start,
(lpc_ctrl->mem_base >> PAGE_SHIFT) + vma->vm_pgoff,
@ -229,8 +229,8 @@ static int aspeed_lpc_ctrl_probe(struct platform_device *pdev)
if (rc)
dev_err(dev, "Unable to register device\n");
else
dev_info(dev, "Loaded at 0x%08x (0x%08x)\n",
lpc_ctrl->mem_base, lpc_ctrl->mem_size);
dev_info(dev, "Loaded at %pap (0x%08x)\n",
&lpc_ctrl->mem_base, lpc_ctrl->mem_size);
return rc;
}