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From: Ludovic Desroches <ludovic.desroches@atmel.com>
To: <ulf.hansson@linaro.org>, <adrian.hunter@intel.com>
Cc: <linux-kernel@vger.kernel.org>, <linux-mmc@vger.kernel.org>,
	<nicolas.ferre@atmel.com>,
	Ludovic Desroches <ludovic.desroches@atmel.com>
Subject: [PATCH v2 0/3] SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST removal
Date: Mon, 4 Apr 2016 17:27:52 +0200	[thread overview]
Message-ID: <1459783675-7798-1-git-send-email-ludovic.desroches@atmel.com> (raw)

Hi,

I have recently observed that the quirk
SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST I have introduced doesn't fix all
the bugs relative to the internal clock disabling while configuring the SD
clock. This delay was introduced because of a re-synchronisation done when
disabling the internal clock.

Unfortunately, we can still have clock stabilization bug even if it occurs
rarely. Moreover, trying to use presets, disabling the internal clock causes an
unexpected switch to the base clock. It should be solved on next revision of
the chip.

For those reasons plus the non acceptance of new quirks, I have decided to
remove it and to implement my own set_clock() function. In ordrer to reduce
code duplication with the sdhci set_clock function, I moved some of the
code in a new sdhci_compute_clock_config() function.

Regards

Changes:
- v2:
  - sdhci_compute_clock_config uses a returned value instead of an
  out-parameter to provide the clock configuration.


Ludovic Desroches (3):
  mmc: sdhci: introduce sdhci_compute_clock_config
  mmc: sdhci-of-at91: implement specific set_clock function
  mmc: sdhci: removal of SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST

 drivers/mmc/host/sdhci-of-at91.c | 48 ++++++++++++++++++++++++++++++++++++++--
 drivers/mmc/host/sdhci.c         | 31 +++++++++++++++++---------
 drivers/mmc/host/sdhci.h         |  6 +----
 3 files changed, 67 insertions(+), 18 deletions(-)

-- 
2.5.0

             reply	other threads:[~2016-04-04 15:27 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-04 15:27 Ludovic Desroches [this message]
2016-04-04 15:27 ` [PATCH v2 1/3] mmc: sdhci: introduce sdhci_compute_clock_config Ludovic Desroches
2016-04-06 12:37   ` Adrian Hunter
2016-04-06 15:04     ` Ludovic Desroches
2016-04-06 15:13       ` Ludovic Desroches
2016-04-07  7:47       ` Adrian Hunter
2016-04-04 15:27 ` [PATCH v2 2/3] mmc: sdhci-of-at91: implement specific set_clock function Ludovic Desroches
2016-04-04 15:27 ` [PATCH v2 3/3] mmc: sdhci: removal of SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST Ludovic Desroches

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