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Groups > linux.kernel > #1373194 > unrolled thread

[PATCH v3 0/3] SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST removal

Started byLudovic Desroches <ludovic.desroches@atmel.com>
First post2016-04-07 11:20 +0200
Last post2016-04-13 14:00 +0200
Articles 2 — 2 participants

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  [PATCH v3 0/3] SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST removal Ludovic Desroches <ludovic.desroches@atmel.com> - 2016-04-07 11:20 +0200
    Re: [PATCH v3 0/3] SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST removal Ulf Hansson <ulf.hansson@linaro.org> - 2016-04-13 14:00 +0200

#1373194 — [PATCH v3 0/3] SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST removal

FromLudovic Desroches <ludovic.desroches@atmel.com>
Date2016-04-07 11:20 +0200
Subject[PATCH v3 0/3] SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST removal
Message-ID<rlegy-1Az-7@gated-at.bofh.it>
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:
- v3:
  - s/sdhci_compute_clock_config/sdhci_calc_clk.
  - don't update actual_clock in sdhci_calc_clk but return its value as an
  output parameter.
- 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         | 34 ++++++++++++++++++----------
 drivers/mmc/host/sdhci.h         |  7 ++----
 3 files changed, 70 insertions(+), 19 deletions(-)

-- 
2.5.0

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#1377858

FromUlf Hansson <ulf.hansson@linaro.org>
Date2016-04-13 14:00 +0200
Message-ID<rnrCH-Gd-41@gated-at.bofh.it>
In reply to#1373194
On 7 April 2016 at 11:13, Ludovic Desroches <ludovic.desroches@atmel.com> wrote:
> 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:
> - v3:
>   - s/sdhci_compute_clock_config/sdhci_calc_clk.
>   - don't update actual_clock in sdhci_calc_clk but return its value as an
>   output parameter.
> - 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         | 34 ++++++++++++++++++----------
>  drivers/mmc/host/sdhci.h         |  7 ++----
>  3 files changed, 70 insertions(+), 19 deletions(-)
>
> --
> 2.5.0
>

Thanks, applied for next with some minor updates to change logs.

Kind regards
Uffe

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