From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 74449C432C0 for ; Fri, 22 Nov 2019 19:50:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 45C5B2073F for ; Fri, 22 Nov 2019 19:50:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574452200; bh=zvZPTTni/ycZBbfQvl6iJVAj8L2x55SrskgiKQVLozY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=OfN5ODgepB3+0uWcW7P6ItSVJMyjAwaMvJwi2LMlI+zU6Sgs6RdmkAcvFV6AuPNZn yVZUwLZHAXwsUoVMZb2DIsqv78kl4F+mlJd6ul7OIp+NtTF7SypOQBK940BpMcSQPn 21umeKlGtEC4sAhlTDQnqRWRpxqCor2QhGgAhJoQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727684AbfKVTt7 (ORCPT ); Fri, 22 Nov 2019 14:49:59 -0500 Received: from mail.kernel.org ([198.145.29.99]:50224 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727655AbfKVTtz (ORCPT ); Fri, 22 Nov 2019 14:49:55 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E88C02075E; Fri, 22 Nov 2019 19:49:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574452195; bh=zvZPTTni/ycZBbfQvl6iJVAj8L2x55SrskgiKQVLozY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=McXiv1nmAk2HDAvSGdzHuh87jp+8mE+naw7fbmP9D/u4hAn2Recw46TsN9cDB0c5U 9wxzC2Z1dM8kTA6+Yr2K3Wu4qVuhelFnQka+ckRKfHHKfB+ctGuZ0efqrm3iO3qOjh ckw7Ph+GaMH4Pt9qbYFYl/UrcT+UWJwsXbkhorao= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Hans de Goede , youling 257 , Jarkko Nikula , Mika Westerberg , Wolfram Sang , stable@kernel.org, Sasha Levin , linux-i2c@vger.kernel.org, linux-acpi@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 19/21] i2c: acpi: Force bus speed to 400KHz if a Silead touchscreen is present Date: Fri, 22 Nov 2019 14:49:29 -0500 Message-Id: <20191122194931.24732-19-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191122194931.24732-1-sashal@kernel.org> References: <20191122194931.24732-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Hans de Goede [ Upstream commit 7574c0db2e68c4d0bae9d415a683bdd8b2a761e9 ] Many cheap devices use Silead touchscreen controllers. Testing has shown repeatedly that these touchscreen controllers work fine at 400KHz, but for unknown reasons do not work properly at 100KHz. This has been seen on both ARM and x86 devices using totally different i2c controllers. On some devices the ACPI tables list another device at the same I2C-bus as only being capable of 100KHz, testing has shown that these other devices work fine at 400KHz (as can be expected of any recent I2C hw). This commit makes i2c_acpi_find_bus_speed() always return 400KHz if a Silead touchscreen controller is present, fixing the touchscreen not working on devices which ACPI tables' wrongly list another device on the same bus as only being capable of 100KHz. Specifically this fixes the touchscreen on the Jumper EZpad 6 m4 not working. Reported-by: youling 257 Tested-by: youling 257 Signed-off-by: Hans de Goede Reviewed-by: Jarkko Nikula Acked-by: Mika Westerberg [wsa: rewording warning a little] Signed-off-by: Wolfram Sang Cc: stable@kernel.org Signed-off-by: Sasha Levin --- drivers/i2c/i2c-core-acpi.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c index 847d9bf6744c2..df9800aaeac71 100644 --- a/drivers/i2c/i2c-core-acpi.c +++ b/drivers/i2c/i2c-core-acpi.c @@ -43,6 +43,7 @@ struct i2c_acpi_lookup { int index; u32 speed; u32 min_speed; + u32 force_speed; }; static int i2c_acpi_fill_info(struct acpi_resource *ares, void *data) @@ -240,6 +241,19 @@ i2c_acpi_match_device(const struct acpi_device_id *matches, return acpi_match_device(matches, &client->dev); } +static const struct acpi_device_id i2c_acpi_force_400khz_device_ids[] = { + /* + * These Silead touchscreen controllers only work at 400KHz, for + * some reason they do not work at 100KHz. On some devices the ACPI + * tables list another device at their bus as only being capable + * of 100KHz, testing has shown that these other devices work fine + * at 400KHz (as can be expected of any recent i2c hw) so we force + * the speed of the bus to 400 KHz if a Silead device is present. + */ + { "MSSL1680", 0 }, + {} +}; + static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level, void *data, void **return_value) { @@ -258,6 +272,9 @@ static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level, if (lookup->speed <= lookup->min_speed) lookup->min_speed = lookup->speed; + if (acpi_match_device_ids(adev, i2c_acpi_force_400khz_device_ids) == 0) + lookup->force_speed = 400000; + return AE_OK; } @@ -295,7 +312,16 @@ u32 i2c_acpi_find_bus_speed(struct device *dev) return 0; } - return lookup.min_speed != UINT_MAX ? lookup.min_speed : 0; + if (lookup.force_speed) { + if (lookup.force_speed != lookup.min_speed) + dev_warn(dev, FW_BUG "DSDT uses known not-working I2C bus speed %d, forcing it to %d\n", + lookup.min_speed, lookup.force_speed); + return lookup.force_speed; + } else if (lookup.min_speed != UINT_MAX) { + return lookup.min_speed; + } else { + return 0; + } } EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed); -- 2.20.1