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From: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
To: adrian.hunter@intel.com, ulf.hansson@linaro.org,
	robh+dt@kernel.org, evgreen@chromium.org, dianders@google.com
Cc: asutoshd@codeaurora.org, riteshh@codeaurora.org,
	stummala@codeaurora.org, sayalil@codeaurora.org,
	linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
	Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
Subject: [PATCH V5 0/2] Re-initialize DLL when MCLK is gated dynamically
Date: Mon, 12 Nov 2018 12:22:15 +0530	[thread overview]
Message-ID: <1542005537-19154-1-git-send-email-vbadigan@codeaurora.org> (raw)

On few SDHCI-MSM controllers, the host controller's clock tuning
circuit may go out of sync if controller clocks are gated which
eventually, result in data CRC and command CRC/timeout errors.
To fix this issue, the DLL needs to be re-initialized and restored with
its old settings once clocks are ungated. SDHC cotroller on SDM845 SOC
has this limitation.

Changes since V4:
	- Exactly same as V3, posted multiple mails for V4.
	So to avoid confusion updating it as V5.

Changes since V3:
	- Introduced SoC specific dt compatible string for sdhci-msm
	controller
	- Moved the condition which checks whether tuning is needed or
	not, to a common function.

Changes since V2:
	- Removed an unused variable.
	- Renamed the newly introduced flags to be more meaningful.
	- Added new dt compatible string for SDM845 SOC.

Changes since V1:
	- Replaced dt flag with a dt compatible string to
	indicate SHDCI-MSM controller varients which need this fix.
	- Moved the DLL settings restoration logic from request 
	context to platform driver runtime pm context.

Tested on: sdm845
Veerabhadrarao Badiganti (2):
  dt-bindings: mmc: sdhci-msm: Add SoC-specific compatible strings
  mmc: sdhci-msm: Re-initialize DLL if MCLK is gated dynamically

 .../devicetree/bindings/mmc/sdhci-msm.txt          | 21 ++++--
 drivers/mmc/host/sdhci-msm.c                       | 78 +++++++++++++++++++---
 2 files changed, 84 insertions(+), 15 deletions(-)

-- 
Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.


             reply	other threads:[~2018-11-12  6:52 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-12  6:52 Veerabhadrarao Badiganti [this message]
2018-11-12  6:52 ` [PATCH V5 1/2] dt-bindings: mmc: sdhci-msm: Add SoC-specific compatible strings Veerabhadrarao Badiganti
2018-11-13  0:20   ` Rob Herring
2018-11-12  6:52 ` [PATCH V5 2/2] mmc: sdhci-msm: Re-initialize DLL if MCLK is gated dynamically Veerabhadrarao Badiganti
2018-11-19 18:50   ` Evan Green
2018-11-20  9:29 ` [PATCH V5 0/2] Re-initialize DLL when " Ulf Hansson

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