linux-kernel - [PATCH 3/3 v2] gspca_zc3xx: Enable short exposure times for OV7648

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Date:   Fri, 25 May 2018 11:08:43 +0200
From:   Ondrej Zary <linux@...nbow-software.org>
To:     Hans Verkuil <hverkuil@...all.nl>
Cc:     linux-media@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 3/3 v2] gspca_zc3xx: Enable short exposure times for OV7648

The 50Hz and 60Hz power line frequency settings disable short (1/120s
and 1/100s) exposure times for banding filter (causing overexposed
image near lamps). No flicker setting enables them (when banding
filter is disabled and they're not used).

Seems that the logic is just the wrong way around.
(This bug came from the Windows driver.)

Signed-off-by: Ondrej Zary <linux@...nbow-software.org>
---
 drivers/media/usb/gspca/zc3xx.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/media/usb/gspca/zc3xx.c b/drivers/media/usb/gspca/zc3xx.c
index c72f2d9167d9..cf21991e3d99 100644
--- a/drivers/media/usb/gspca/zc3xx.c
+++ b/drivers/media/usb/gspca/zc3xx.c
@@ -3186,7 +3186,8 @@ static const struct usb_action ov7620_InitialScale[] = {	/* 320x240 */
 static const struct usb_action ov7620_50HZ[] = {
 	{0xdd, 0x00, 0x0100},	/* 00,01,00,dd */
 	{0xaa, 0x2b, 0x0096},	/* 00,2b,96,aa */
-	{0xaa, 0x75, 0x008a},	/* 00,75,8a,aa */
+	/* enable 1/120s & 1/100s exposures for banding filter */
+	{0xaa, 0x75, 0x008e},
 	{0xaa, 0x2d, 0x0005},	/* 00,2d,05,aa */
 	{0xa0, 0x00, ZC3XX_R190_EXPOSURELIMITHIGH},	/* 01,90,00,cc */
 	{0xa0, 0x04, ZC3XX_R191_EXPOSURELIMITMID},	/* 01,91,04,cc */
@@ -3202,7 +3203,8 @@ static const struct usb_action ov7620_50HZ[] = {
 static const struct usb_action ov7620_60HZ[] = {
 	{0xdd, 0x00, 0x0100},			/* 00,01,00,dd */
 	{0xaa, 0x2b, 0x0000},			/* 00,2b,00,aa */
-	{0xaa, 0x75, 0x008a},			/* 00,75,8a,aa */
+	/* enable 1/120s & 1/100s exposures for banding filter */
+	{0xaa, 0x75, 0x008e},
 	{0xaa, 0x2d, 0x0005},			/* 00,2d,05,aa */
 	{0xa0, 0x00, ZC3XX_R190_EXPOSURELIMITHIGH}, /* 01,90,00,cc */
 	{0xa0, 0x04, ZC3XX_R191_EXPOSURELIMITMID}, /* 01,91,04,cc */
@@ -3221,7 +3223,8 @@ static const struct usb_action ov7620_60HZ[] = {
 static const struct usb_action ov7620_NoFliker[] = {
 	{0xdd, 0x00, 0x0100},			/* 00,01,00,dd */
 	{0xaa, 0x2b, 0x0000},			/* 00,2b,00,aa */
-	{0xaa, 0x75, 0x008e},			/* 00,75,8e,aa */
+	/* disable 1/120s & 1/100s exposures for banding filter */
+	{0xaa, 0x75, 0x008a},
 	{0xaa, 0x2d, 0x0001},			/* 00,2d,01,aa */
 	{0xa0, 0x00, ZC3XX_R190_EXPOSURELIMITHIGH}, /* 01,90,00,cc */
 	{0xa0, 0x04, ZC3XX_R191_EXPOSURELIMITMID}, /* 01,91,04,cc */
-- 
Ondrej Zary