From patchwork Tue Jan 17 00:52:52 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Stultz X-Patchwork-Id: 91596 Delivered-To: patches@linaro.org Received: by 10.140.20.99 with SMTP id 90csp267312qgi; Mon, 16 Jan 2017 16:53:02 -0800 (PST) X-Received: by 10.84.205.69 with SMTP id o5mr53648526plh.70.1484614382682; Mon, 16 Jan 2017 16:53:02 -0800 (PST) Return-Path: Received: from mail-pg0-x232.google.com (mail-pg0-x232.google.com. [2607:f8b0:400e:c05::232]) by mx.google.com with ESMTPS id g188si23139617pfc.136.2017.01.16.16.53.02 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 16 Jan 2017 16:53:02 -0800 (PST) Received-SPF: pass (google.com: domain of john.stultz@linaro.org designates 2607:f8b0:400e:c05::232 as permitted sender) client-ip=2607:f8b0:400e:c05::232; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org; spf=pass (google.com: domain of john.stultz@linaro.org designates 2607:f8b0:400e:c05::232 as permitted sender) smtp.mailfrom=john.stultz@linaro.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: by mail-pg0-x232.google.com with SMTP id t6so14251223pgt.3 for ; Mon, 16 Jan 2017 16:53:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=IGTT6YVzGSFz2F9Zo1AJDGSlDu7UZzqYvjTPYrfDt3s=; b=KMC1R+a250oExvRJ9v8WxyZR5VBXeJvJ5XhTQ8VFfVX+BYBtFBRN2S62yLU52O6R/E eTImg+qoxzNAkLXBH5oITB/ADrexaPHnO9dU85PiIqXoOBSqCjAs++7nArs7yjnr98aH nvW1YKakJMcfKIs7vBwqu4hOn8YjcqhfXPIsk= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=IGTT6YVzGSFz2F9Zo1AJDGSlDu7UZzqYvjTPYrfDt3s=; b=QFcAA7ooRmOHohgSM8RJuA2jCHAtgul3dt26WSvJHxyThvOm+ioRuzpF0wpad8PvMp PPrgJ40tXNk7N8XgO1fnOc/d/Xbvd4Zk6gJ+3yJu4Y7LwwJQCw8AKmQYWTNRKlmooYrF gA/KBAWdyU4KUTi8bN2pvasyTW4q6qyuYwX2dk8PM2uML8I2hTOkbasTtNjnxlKnrjFw 9436y9P5XRHOA5l1OYD4IT3J1Ey20ws58b+GgI0eq9d3pezoRl5/P/4bE/urb5ocfqLu zBLXxKZJFmrqTmY+unNvQWEeS8lXxnEMFZdT/OOVX3fQBkslkgjpoFxu1IYqOhUbploo mTZQ== X-Gm-Message-State: AIkVDXLJpDPiuLqFoihE1jVvPXLH+OeF7W21UDZltmRrUgsbJtVWkfTlS4MIjnBqwT9Thmq7fD4= X-Received: by 10.98.71.199 with SMTP id p68mr40551209pfi.104.1484614382426; Mon, 16 Jan 2017 16:53:02 -0800 (PST) Return-Path: Received: from localhost.localdomain ([2601:1c2:1002:83f0:4e72:b9ff:fe99:466a]) by smtp.gmail.com with ESMTPSA id q19sm50220516pfl.21.2017.01.16.16.53.01 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 16 Jan 2017 16:53:01 -0800 (PST) From: John Stultz To: lkml Cc: John Stultz , David Airlie , Archit Taneja , Wolfram Sang , Lars-Peter Clausen , Laurent Pinchart , dri-devel@lists.freedesktop.org Subject: [PATCH 6/6] drm/bridge: adv7511: Re-write the i2c address before EDID probing Date: Mon, 16 Jan 2017 16:52:52 -0800 Message-Id: <1484614372-15342-7-git-send-email-john.stultz@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1484614372-15342-1-git-send-email-john.stultz@linaro.org> References: <1484614372-15342-1-git-send-email-john.stultz@linaro.org> I've found that by just turning the chip on and off via the POWER_DOWN register, I end up getting i2c_transfer errors on HiKey. Investigating further, it seems some of the register state in the regmap cache is getting lost, likely as the device registers were reset during power off. Thus this patch simply re-writes the i2c address to the ADV7511_REG_EDID_I2C_ADDR register to ensure its properly set before we try to read the EDID data. Cc: David Airlie Cc: Archit Taneja Cc: Wolfram Sang Cc: Lars-Peter Clausen Cc: Laurent Pinchart Cc: dri-devel@lists.freedesktop.org Signed-off-by: John Stultz --- v4: New approach to make the EDID_I2C_ADDR register sane, as suggested by Laurent --- drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) -- 2.7.4 diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c index d216f61..0ed89ea 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c @@ -573,9 +573,17 @@ static int adv7511_get_modes(struct adv7511 *adv7511, unsigned int count; /* Reading the EDID only works if the device is powered */ - if (!adv7511->powered) + if (!adv7511->powered) { + unsigned int edid_i2c_addr = + (adv7511->i2c_main->addr << 1) + 4; + __adv7511_power_on(adv7511); + /* Reset the EDID_I2C_ADDR register as it might be cleared */ + regmap_write(adv7511->regmap, ADV7511_REG_EDID_I2C_ADDR, + edid_i2c_addr); + } + edid = drm_do_get_edid(connector, adv7511_get_edid_block, adv7511); if (!adv7511->powered)