From nobody Tue Feb 10 01:59:57 2026 Received: from out-172.mta0.migadu.com (out-172.mta0.migadu.com [91.218.175.172]) (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 0124F39AC9 for ; Fri, 26 Apr 2024 22:57:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714172279; cv=none; b=XChefkU0twjfK5MSj+26dLhNdKuFGo33doO5J3D+VlrW7bhHGgGDv08/HVQ5SfGPyFMWm2W9m8aaLLKr9A+DOzVtbnVrclNBNW5LNlI+Id7mouh/wx1Dgqj7dGazTGBHGGVEtRZJ6HNsLe+eqW3D4ya/37QlMZQUMxrwy3t+7oU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714172279; c=relaxed/simple; bh=jcYLChDAgnIUe4+iN8D3/9NndAF22/1Z60vNxCuSZTU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=erWf2uX4+dQw9O0ZBNyJWZAN4klLAzQMfZbLdebeyuAkSWKGU3056Oo0OXe2M1rhS+SzLhNnny5ui/aKsgOpHSpex3eYSlbWOATvmdFAA1IxiJgPlNZcE7zRDAN8u8gEhd/64pqiVtFMz8X17+iqTnNOY9ATu+8ttIqAd1SWmQA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=kl.wtf; spf=pass smtp.mailfrom=kl.wtf; dkim=pass (2048-bit key) header.d=kl.wtf header.i=@kl.wtf header.b=PyMDwgGJ; arc=none smtp.client-ip=91.218.175.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=kl.wtf Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kl.wtf Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kl.wtf header.i=@kl.wtf header.b="PyMDwgGJ" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kl.wtf; s=key1; t=1714172276; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=4KU3jl0WoeassL0fsNyvxyf1+jr7Lzh8USMHCS2SFuk=; b=PyMDwgGJogmpa6f+Up4ClCDkkfbFDqgE0FxFFdokAgFB6B05qFPdsdg1iAe+0lyH8biu2k VuW9RVfhDJc1AMP2A7zp/0R5DLW5yDpYh5s2ootpgOVliKPMlHKVjcLzOIXSlhWGOpn2PS czThUf0Rb/1TRQHS2nhkcQmgcvUAzb7Pcq5XrQ2YjAfZdxhYE8pfR6JkTHOOcWggLboTwS 8VApmOQEq0TVmWlJS1mmV1HolJ54ZzrmhB/FTSvrzCD6MR6Awo3W7bCFZZSNb5UA74pMgZ eDQ/YMbwkzbmggPyzAo+jL3XiNFdCxH9dBBb78sFnUWvVseSmL+yA2tRulYl5A== From: Kenny Levinsen To: Jiri Kosina , Dmitry Torokhov , Benjamin Tissoires , Douglas Anderson , Hans de Goede , Maxime Ripard , Kai-Heng Feng , Johan Hovold , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, Radoslaw Biernacki , Lukasz Majczak Cc: Kenny Levinsen Subject: [PATCH v3 2/3] HID: i2c-hid: Retry HID descriptor read to wake up STM devices Date: Sat, 27 Apr 2024 00:47:08 +0200 Message-ID: <20240426225739.2166-3-kl@kl.wtf> In-Reply-To: <20240426225739.2166-1-kl@kl.wtf> References: <20240426225739.2166-1-kl@kl.wtf> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Some STM microcontrollers need 400=C2=B5s after rising clock edge in order = to come out of their deep sleep state. This in turn means that the first command sent to them will fail on a bus error. Retry once on bus error to see if the device came alive, otherwise treat the error as if no device was present like before. Link: https://lore.kernel.org/all/20240405102436.3479210-1-lma@chromium.org= /#t Co-developed-by: Radoslaw Biernacki Co-developed-by: Lukasz Majczak Tested-by: Lukasz Majczak Reviewed-by: Lukasz Majczak Signed-off-by: Kenny Levinsen --- drivers/hid/i2c-hid/i2c-hid-core.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-h= id-core.c index 6ffa43d245b4..6ac1b11fb675 100644 --- a/drivers/hid/i2c-hid/i2c-hid-core.c +++ b/drivers/hid/i2c-hid/i2c-hid-core.c @@ -991,8 +991,17 @@ static int __i2c_hid_core_probe(struct i2c_hid *ihid) struct hid_device *hid =3D ihid->hid; int ret; =20 + /* + * Some STM-based devices need 400=C2=B5s after a rising clock edge to wa= ke + * from deep sleep, which in turn means that our first command will + * fail on a bus error. Retry the command in this case. + */ ret =3D i2c_hid_fetch_hid_descriptor(ihid); - if (ret < 0) { + if (ret =3D=3D -ENXIO) { + usleep_range(400, 500); + ret =3D i2c_hid_fetch_hid_descriptor(ihid); + } + if (ret) { i2c_hid_dbg(ihid, "failed to fetch HID descriptor: %d\n", ret); return ret; } --=20 2.44.0