From nobody Sun Feb 8 06:04:54 2026 Received: from esa.microchip.iphmx.com (esa.microchip.iphmx.com [68.232.153.233]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6F9C032939F for ; Fri, 6 Feb 2026 16:33:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=68.232.153.233 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770395619; cv=none; b=GlhmDyhveFo2fPKBhRDxduRjMqOdVVajPBK7artgbyL7rk7c2X8LJB54BvbKX+GKdEbJbw9cV7JtwQWUx7fPqA89p7yR+S8RgeT97rYYAZ3VItkHLFjJDQmat1kuKBD2kwEO9pPx3Ar1CetbpUAlVJWPlImGM7JNPszNYUSjTI4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770395619; c=relaxed/simple; bh=13xPOSUUUaD/I1zhNhcZTz9p+bmWQ3zNj70Z1lcWN78=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=qsIe/FQNZNO6fKFffkUe4flX7XfS5e3LiKhuAlxzBQxgYGlJ0U+yfMk6/ylpm6AWCJT9cJs4TsbbUH5IUFM7+wjRxoBQ6yFsJz/tdq8XwWzkbH8UMLinUXAWznXr5G9HuigiiybXFT7wyQpPYZmJmRFBaoE1F2sZV2slxH9qXvw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=microchip.com; spf=pass smtp.mailfrom=microchip.com; dkim=pass (2048-bit key) header.d=microchip.com header.i=@microchip.com header.b=zp8okoxF; arc=none smtp.client-ip=68.232.153.233 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=microchip.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=microchip.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=microchip.com header.i=@microchip.com header.b="zp8okoxF" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1770395620; x=1801931620; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=13xPOSUUUaD/I1zhNhcZTz9p+bmWQ3zNj70Z1lcWN78=; b=zp8okoxF8sbS/oC86HBBYL9isvXcdrDZWUJ3fd05Y5kjckJgNp6Nrk6z wyv0cMUKQRAwqwKQTLKelkATvSAs9sG96lAjdBZgwRPLXL6QB4i7RQje2 atREu5eYECFbWLQ+GWz5AxBofvH3+9UGmOmP3otBiEwO8tVnRqM3TogWj 4XWs8IBLpVU5yE87Q+cUnwtAksoHgNVnYPMDag7eSHuMhO8ddc+ntWn1n O3NLg/vEyENrN6UrB4/0STb55r9hVj16yZz+9dkCHhtFI8x98lAAC+bcG 1c+6cAWf/cZX8cxne80JLRg5BQ5bSquoXARoNPjUtfHFnkPbyuOOOx9gc A==; X-CSE-ConnectionGUID: +vtqsw7UT6C57kYimqV5Qw== X-CSE-MsgGUID: effixkjdTWCvVEEr422z4Q== X-IronPort-AV: E=Sophos;i="6.21,276,1763449200"; d="scan'208";a="284428663" X-Amp-Result: SKIPPED(no attachment in message) Received: from unknown (HELO email.microchip.com) ([170.129.1.10]) by esa5.microchip.iphmx.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Feb 2026 09:33:39 -0700 Received: from chn-vm-ex03.mchp-main.com (10.10.87.152) by chn-vm-ex3.mchp-main.com (10.10.87.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.2.2562.35; Fri, 6 Feb 2026 09:33:01 -0700 Received: from ROU-LL-M70749.microchip.com (10.10.85.11) by chn-vm-ex03.mchp-main.com (10.10.85.151) with Microsoft SMTP Server id 15.1.2507.58 via Frontend Transport; Fri, 6 Feb 2026 09:33:00 -0700 From: Romain Sioen To: CC: , , Romain Sioen Subject: [PATCH] HID: mcp2221: cancel last I2C command on read error Date: Fri, 6 Feb 2026 17:32:58 +0100 Message-ID: <20260206163258.130584-1-romain.sioen@microchip.com> X-Mailer: git-send-email 2.53.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When an I2C SMBus read operation fails, the MCP2221 internal state machine may not reset correctly, causing subsequent transactions to fail. By adding a short delay and explicitly cancelling the last command, we ensure the device is ready for the next operation. Fix an issue where i2cdetect was not able to detect all devices correctly on the bus. Signed-off-by: Romain Sioen --- drivers/hid/hid-mcp2221.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/hid/hid-mcp2221.c b/drivers/hid/hid-mcp2221.c index 64dcedbcc0fc9..5eefdcc477b9d 100644 --- a/drivers/hid/hid-mcp2221.c +++ b/drivers/hid/hid-mcp2221.c @@ -353,6 +353,8 @@ static int mcp_i2c_smbus_read(struct mcp2221 *mcp, usleep_range(90, 100); retries++; } else { + usleep_range(980, 1000); + mcp_cancel_last_cmd(mcp); return ret; } } else { --=20 2.53.0