From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELuWQwWB00PCDj1nk13JxfGDVBguO8Hl+VZkM1cbSrlrbqg+LlVjOuEva3QQUElvjkk4Fd04 ARC-Seal: i=1; a=rsa-sha256; t=1521800304; cv=none; d=google.com; s=arc-20160816; b=EHf/R1pp29eVtsQzkpJXbymtgK912JGzj5E1/4dL8iwWjHs1flc0TXLLvVLEQlaAY8 18RfBHzLDnpCiMnrEHY7SeCOaQ2FDRePJKQh2pfmY/sI4CdyMGAnHSFsxru3v1i2cGJ3 fB2j8m3pjcYSAdsOQ7SbVYGVtTQAPDrbzJ3MlPNqwkhL3JdRfpQ0OuqLiiUtDEbKEn6b dBP+Pj/mtu+hrAoxlCgVw1cIozuXJ3UHB5VaRDTaKc4xOnpXfWonXHH6AWbVhTFOBgEC XTM2VljnDqLoR8RFZhndB9s6Qc4Afo1q3rKhM2hDceW7o5lvtPiFSpdPScezX569D2Ys FQ8Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=1TQoPuRHd/4iDYRFrjy7M+k7/Hgq8NYk/KiaWC8KVvE=; b=fh7bKp7bk/DpVr6jL9D61XXQ2Lo1XBcFvU1i2J1jVd3YqZF1keI/7ZQFZoAnLiO3qG ErbB95lcF4IEGuThRTzhDqvmroVwCmDXf0qsV8XcKrIl57AJ/oIIfeIKslE6spjvfWsm JQYfIYKQcIU85qSKdEtPJcfo6lV/Qn8d/6A4uZpA9vPTxSWvhVIJgENTTHnuJKUtu3bE mE8sCDi1E2Q7jQWmXV6lg/T5r53ToZPVPXGSfhERe5ME48ufWSGopiTdEqIFhF6wPSST ZuPTmtVxyKtrBCcEZpgwt9ST1iRnAJKxFcb3eY74BP/AC28GrQTBUyKay1TAQfE9MGID Zxwg== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Edgar Cherkasov , Michael Brunner , Viktor Krasnov , Jean Delvare , Mika Westerberg , Wolfram Sang , Sasha Levin Subject: [PATCH 3.18 07/47] i2c: i2c-scmi: add a MS HID Date: Fri, 23 Mar 2018 10:54:58 +0100 Message-Id: <20180323094248.435128683@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180323094248.117679641@linuxfoundation.org> References: <20180323094248.117679641@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1595722411556560563?= X-GMAIL-MSGID: =?utf-8?q?1595723275753310523?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Edgar Cherkasov [ Upstream commit e058e7a4bc89104540a8a303682248614b5df6f1 ] Description of the problem: - i2c-scmi driver contains only two identifiers "SMBUS01" and "SMBUSIBM"; - the fist HID (SMBUS01) is clearly defined in "SMBus Control Method Interface Specification, version 1.0": "Each device must specify 'SMBUS01' as its _HID and use a unique _UID value"; - unfortunately, BIOS vendors (like AMI) seem to ignore this requirement and implement "SMB0001" HID instead of "SMBUS01"; - I speculate that they do this because only "SMB0001" is hard coded in Windows SMBus driver produced by Microsoft. This leads to following situation: - SMBus works out of box in Windows but not in Linux; - board vendors are forced to add correct "SMBUS01" HID to BIOS to make SMBus work in Linux. Moreover the same board vendors complain that tools (3-rd party ASL compiler) do not like the "SMBUS01" identifier and produce errors. So they need to constantly patch the compiler for each new version of BIOS. As it is very unlikely that BIOS vendors implement a correct HID in future, I would propose to consider whether it is possible to work around the problem by adding MS HID to the Linux i2c-scmi driver. v2: move the definition of the new HID to the driver itself. Signed-off-by: Edgar Cherkasov Signed-off-by: Michael Brunner Acked-by: Viktor Krasnov Reviewed-by: Jean Delvare Reviewed-by: Mika Westerberg Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/i2c/busses/i2c-scmi.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/i2c/busses/i2c-scmi.c +++ b/drivers/i2c/busses/i2c-scmi.c @@ -18,6 +18,9 @@ #define ACPI_SMBUS_HC_CLASS "smbus" #define ACPI_SMBUS_HC_DEVICE_NAME "cmi" +/* SMBUS HID definition as supported by Microsoft Windows */ +#define ACPI_SMBUS_MS_HID "SMB0001" + ACPI_MODULE_NAME("smbus_cmi"); struct smbus_methods_t { @@ -51,6 +54,7 @@ static const struct smbus_methods_t ibm_ static const struct acpi_device_id acpi_smbus_cmi_ids[] = { {"SMBUS01", (kernel_ulong_t)&smbus_methods}, {ACPI_SMBUS_IBM_HID, (kernel_ulong_t)&ibm_smbus_methods}, + {ACPI_SMBUS_MS_HID, (kernel_ulong_t)&smbus_methods}, {"", 0} }; MODULE_DEVICE_TABLE(acpi, acpi_smbus_cmi_ids);