Re: [PATCH v2 2/3] video: xilinxfb: Do not use out_be32 IO function

[Timur Tabi]

On Thu, May 30, 2013 at 5:04 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
> This is probably missing barriers, and is wrong on systems on which
> the endianess of the device is different from the CPU.


I suggest what was done in fsl_ssi.c:

#ifdef PPC
#define read_ssi(addr)             in_be32(addr)
#define write_ssi(val, addr)         out_be32(addr, val)
#define write_ssi_mask(addr, clear, set) clrsetbits_be32(addr, clear, set)
#elif defined ARM
#define read_ssi(addr)             readl(addr)
#define write_ssi(val, addr)         writel(val, addr)
/*
 * FIXME: Proper locking should be added at write_ssi_mask caller level
 * to ensure this register read/modify/write sequence is race free.
 */
static inline void write_ssi_mask(u32 __iomem *addr, u32 clear, u32 set)
{
    u32 val = readl(addr);
    val = (val & ~clear) | set;
    writel(val, addr);
}
#endif
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