On 12/03/2014 02:42 PM, Tomi Valkeinen wrote:
Hi Dan, Jyri,
On 03/12/14 14:22, Dan Carpenter wrote:
Hello Tomi Valkeinen,
The patch f5bab2229190: "OMAPDSS: HDMI: Add OMAP5 HDMI support" from
Mar 13, 2014, leads to the following static checker warning:
drivers/video/fbdev/omap2/dss/hdmi5_core.c:719 hdmi5_core_audio_config()
warn: '(3) - (4)' negative one
Uh... This is really weird, I have no idea what this warning is or why
it's triggered. I've even looked at the code which triggers it but that
has no documentation. :P Still it seems like something worth looking
into.
I presume it somehow is caused by this line in the dss.h:
#define FLD_MASK(start, end) (((1 << ((start) - (end) + 1)) - 1) << (end))
But I don't quite see why the warnings happens. start=3 and end=4 should
produce valid code there, even if the end result is not what's expected...
drivers/video/fbdev/omap2/dss/hdmi5_core.c
713 /* PCM audio mode */
714 val = (cfg->iec60958_cfg->status[0] & IEC958_AES0_CON_MODE) >> 6;
715 REG_FLD_MOD(base, HDMI_CORE_FC_AUDSCHNLS(2), val, 6, 4);
716
717 /* Source number */
718 val = cfg->iec60958_cfg->status[2] & IEC958_AES2_CON_SOURCE;
719 REG_FLD_MOD(base, HDMI_CORE_FC_AUDSCHNLS(2), val, 3, 4);
^^^^
Aren't these reversed? This seems like an invalid bitfield range.
Good catch! Indeed it's reversed.
Jyri, this is in the hdmi audio side. Can you check it out? Fix is
trivial, but I'd like to know if it has caused wrong configuration, and
if it has, why haven't we noticed anything.
The bits written there are always zero and hardly significant. The HDMI
audio still works after the attached patch.
Best regards,
Jyri
ps. One of these days I am going to have to go through these settings
register by register...
>From 08460e1db02f1babd75b72769e3078462f8e5d81 Mon Sep 17 00:00:00 2001
From: Jyri Sarha <jsarha@xxxxxx>
Date: Wed, 3 Dec 2014 16:24:06 +0200
Subject: [PATCH] OMAPDSS: hdmi5: Fix bit field for IEC958_AES2_CON_SOURCE
The bit field for IEC958_AES2_CON_SOURCE is bit 3-0 in
HDMI_CORE_FC_AUDSCHNLS2, not imaginary bits 3-4 (reverse order).
Signed-off-by: Jyri Sarha <jsarha@xxxxxx>
---
drivers/video/fbdev/omap2/dss/hdmi5_core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/video/fbdev/omap2/dss/hdmi5_core.c b/drivers/video/fbdev/omap2/dss/hdmi5_core.c
index a711579..a3cfe3d 100644
--- a/drivers/video/fbdev/omap2/dss/hdmi5_core.c
+++ b/drivers/video/fbdev/omap2/dss/hdmi5_core.c
@@ -716,7 +716,7 @@ static void hdmi5_core_audio_config(struct hdmi_core_data *core,
/* Source number */
val = cfg->iec60958_cfg->status[2] & IEC958_AES2_CON_SOURCE;
- REG_FLD_MOD(base, HDMI_CORE_FC_AUDSCHNLS(2), val, 3, 4);
+ REG_FLD_MOD(base, HDMI_CORE_FC_AUDSCHNLS(2), val, 3, 0);
/* Channel number right 0 */
REG_FLD_MOD(base, HDMI_CORE_FC_AUDSCHNLS(3), 2, 3, 0);
--
1.7.9.5
