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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: QPYVI0CI/cC76lZFjZMcSe7DSMdrwOMrMSCFF47JSL/4IWkFOm4Lr0LHVvFFpdsqNrs3FPgQy75hj3SNYc+IBIFADaXFAi6Zn/VY+qzE/17k/NRTsG2kFalEBjEv8uyLZmopCnHcthTsAoA7sx3ri9ueUQtRQb5j925QE4jzreOvk97SsRrrAlJJI4SZyWWRnEXTyr+Tl57tQis1RyiOXFFsrnMIl/V7tBfrCOPdukOVLLK/B3Dfy5UUVIyzrujvYGTQ3gDBSXT0+BjH77nkl7wzDxsCyJuGC0q3ijqCblLtfjKCZ5XT0nRV97h3zHC1+Z5EszoNkV6E8179kCYa3UmAwSUoMMnj7x8GlCnno1i67m+fGdEOI1KCYRlewUcwU8r63ks0Q5QrEkWA2+4DT5aUoFbAxMJ73piBBZoOHeNTrAk+NXHHz3PuFNYIpVPp X-OriginatorOrg: topic.nl X-MS-Exchange-CrossTenant-OriginalArrivalTime: 11 May 2026 17:59:50.7031 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 8f061f0d-76b4-41f0-1abf-08deaf871907 X-MS-Exchange-CrossTenant-Id: 449607a5-3517-482d-8d16-41dd868cbda3 X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=449607a5-3517-482d-8d16-41dd868cbda3;Ip=[13.93.42.39];Helo=[westeu12-emailsignatures-cloud.codetwo.com] X-MS-Exchange-CrossTenant-AuthSource: DB5PEPF00014B9C.eurprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: PA2PR04MB10409 On 11-05-2026 18:06, Jonathan Cameron wrote: > On Sat, 9 May 2026 15:36:19 -0500 > David Lechner wrote: > >> On 5/9/26 10:19 AM, Md Shofiqul Islam wrote: >>> The driver was enabling the internal test signal (INT_TEST), double >>> amplitude (TEST_AMP), and fast frequency (TEST_FREQ_FAST) bits in >>> CONFIG2 during initialization. These bits activate an internal square >>> wave generator intended for device testing and calibration, not normal >>> ECG operation. >>> >>> CONFIG2 defaults to having only the RESERVED bit set after reset, which >>> is the correct value for normal operation. Remove the write entirely >>> since it would just be writing the reset default value. >>> >>> Suggested-by: Mike Looijmans >>> Signed-off-by: Md Shofiqul Islam >>> --- >>> drivers/iio/adc/ti-ads1298.c | 9 --------- >>> 1 file changed, 9 deletions(-) >>> >>> diff --git a/drivers/iio/adc/ti-ads1298.c b/drivers/iio/adc/ti-ads1298.= c >>> index 186bda3087..8957e873e1 100644 >>> --- a/drivers/iio/adc/ti-ads1298.c >>> +++ b/drivers/iio/adc/ti-ads1298.c >>> @@ -615,15 +615,6 @@ static int ads1298_init(struct iio_dev *indio_dev) >>> if (!indio_dev->name) >>> return -ENOMEM; >>> =20 >>> - /* Enable internal test signal, double amplitude, double frequency */ >> This is why comments should say why and not what. If the original author >> had a plan for this, we don't know what it was. >> > Mike, any recollection? > > Anyhow I'm going to apply it anyway given Mike suggested it and fairly > sure it was Mikes' code ;) I think the idea was to have "some" test signal when setting the mux=20 into "test" mode. But indeed, never actually used and as it raises questions, it's better=20 to leave it out. Hence my suggestion. > > Applied. >> I look at the datasheet and the driver. Seems OK since the test signals >> aren't used anywhere in the driver right now. >> >>> - ret =3D regmap_write(priv->regmap, ADS1298_REG_CONFIG2, >>> - ADS1298_MASK_CONFIG2_RESERVED | >>> - ADS1298_MASK_CONFIG2_INT_TEST | >>> - ADS1298_MASK_CONFIG2_TEST_AMP | >>> - ADS1298_MASK_CONFIG2_TEST_FREQ_FAST); >>> - if (ret) >>> - return ret; >>> - >>> val =3D ADS1298_MASK_CONFIG3_RESERVED; /* Must write 1 always */ >>> if (!priv->reg_vref) { >>> /* Enable internal reference */ --=20 Mike Looijmans System Expert TOPIC Embedded Products B.V. Materiaalweg 4, 5681 RJ Best The Netherlands T: +31 (0) 499 33 69 69 E: mike.looijmans@topic.nl W: www.topic.nl