[PATCH 2/5] drm: EDID: Fix bit masking of {X,Y}{OFFSET,PULSE}
Ben Hutchings
ben.hutchings at codethink.co.uk
Tue Nov 13 17:12:04 UTC 2018
Currently we fail to encode any of these fields correctly if they
are large enough to require the top 2 bits. Thankfully none of
the EDID sources here are affected.
The masking and shifting of the top 2 bits (out of 10 for X, 6 for Y)
is only needed in one place so remove the msbs4() macro.
Signed-off-by: Ben Hutchings <ben.hutchings at codethink.co.uk>
---
Documentation/EDID/edid.S | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/Documentation/EDID/edid.S b/Documentation/EDID/edid.S
index ce4b8b4a20b2..8abbf6c24d88 100644
--- a/Documentation/EDID/edid.S
+++ b/Documentation/EDID/edid.S
@@ -48,8 +48,6 @@
((((v1-'@')&0x1f)<<10)+(((v2-'@')&0x1f)<<5)+((v3-'@')&0x1f))
#define swap16(v1) ((v1>>8)+((v1&0xff)<<8))
#define msbs2(v1,v2) ((((v1>>8)&0x0f)<<4)+((v2>>8)&0x0f))
-#define msbs4(v1,v2,v3,v4) \
- (((v1&0x03)>>2)+((v2&0x03)>>4)+((v3&0x03)>>6)+((v4&0x03)>>8))
#define pixdpi2mm(pix,dpi) ((pix*25)/dpi)
#define xsize pixdpi2mm(XPIX,DPI)
#define ysize pixdpi2mm(YPIX,DPI)
@@ -202,12 +200,12 @@ x_snc_off_lsb: .byte XOFFSET&0xff
x_snc_pls_lsb: .byte XPULSE&0xff
/* Bits 7-4 Vertical sync offset lines 4 lsbits (0-63)
Bits 3-0 Vertical sync pulse width lines 4 lsbits (0-63) */
-y_snc_lsb: .byte (YOFFSET<<4)+YPULSE
+y_snc_lsb: .byte ((YOFFSET&0x0f)<<4)+(YPULSE&0x0f)
/* Bits 7-6 Horizontal sync offset pixels 2 msbits
Bits 5-4 Horizontal sync pulse width pixels 2 msbits
Bits 3-2 Vertical sync offset lines 2 msbits
Bits 1-0 Vertical sync pulse width lines 2 msbits */
-xy_snc_msbs: .byte msbs4(XOFFSET,XPULSE,YOFFSET,YPULSE)
+xy_snc_msbs: .byte (((XOFFSET>>8)&3)<<6)+(((XPULSE>>8)&3)<<4)+(((YOFFSET>>4)&3)<<2)+((YPULSE>>4)&3)
/* Horizontal display size, mm, 8 lsbits (0-4095 mm, 161 in) */
x_dsp_size: .byte xsize&0xff
--
Ben Hutchings, Software Developer Codethink Ltd
https://www.codethink.co.uk/ Dale House, 35 Dale Street
Manchester, M1 2HF, United Kingdom
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