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fbdev: sm712: Fix operator precedence in big_swap macro
The big_swap(p) macro was intended to swap bytes within 16-bit halves
of a 32-bit value. However, because the bitwise shift operators (<<, >>)
have higher precedence than the bitwise AND operator (&), the original
code failed to perform any shifting on the masked bits.
For example, 'p & 0xff00ff00 >> 8' was evaluated as 'p &
(0xff00ff00 >> 8)', effectively neutralizing the intended swap.
Fix this by adding parentheses to ensure the bitwise AND is performed
before the shift, correctly implementing the byte swap logic.
Fixes: 1461d66728 ("staging: sm7xxfb: merge sm712fb with fbdev")
Cc: stable@vger.kernel.org
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Helge Deller <deller@gmx.de>
This commit is contained in:
committed by
Helge Deller
parent
b15d708995
commit
5dbe5b65df
@@ -101,7 +101,7 @@ struct modeinit {
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#define mmio_addr 0x00800000
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#define seqw17() smtc_seqw(0x17, 0x30)
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#define big_pixel_depth(p, d) {if (p == 24) {p = 32; d = 32; } }
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#define big_swap(p) ((p & 0xff00ff00 >> 8) | (p & 0x00ff00ff << 8))
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#define big_swap(p) (((p & 0xff00ff00) >> 8) | ((p & 0x00ff00ff) << 8))
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#else
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#define pal_rgb(r, g, b, val) val
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#define big_addr 0
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