Re: [PATCH v5 0/7] Add tuning algorithm for delay chain

From: Ulf Hansson
Date: Mon Mar 25 2024 - 11:52:58 EST


On Wed, 20 Mar 2024 at 23:38, Judith Mendez <jm@xxxxxx> wrote:
>
> This patch series introduces a new tuning algorithm for
> mmc. The new algorithm should be used when delay chain is
> enabled. The ITAPDLY is selected from the largest passing
> window and the buffer is not viewed as a circular buffer.
> The new tuning algorithm is implemented as per the paper
> published here [0] and has been tested on the following
> platforms: AM62x SK, AM62A SK, AM62p SK, AM64x SK, and AM64x
> EVM.
>
> The series also includes a few fixes in the sdhci_am654
> driver on OTAPDLYEN/ITAPDLYEN and ITAPDELSEL.
>
> Changelog:
> v4->v5:
> - Add dll_enable = false
> v3->v4:
> - Add acked-by
> - Remove extra newline
> v2->v3:
> - Remove fixes tags when not needed
> - Fix return for tuning algorithm
> - Fix ITAPDLY_LAST_INDEX
> - Use reverse fir tree order for variable declarations
> - Save all ITAPDLYENA changes in itap_del_ena[]
> - Remove unnecessary parenthesis
> - Remove unnecessary variables
> - Save itapdlyena for HS400 timing
> v1->v2:
> - Remove unnecessary indentations and if/else in
> sdhci_am654_calculate_itap
> - Optimize sdhci_am654_calculate_itap()
> - Call sdhci_am654_write_itapdly() in sdhci_am654_set_clock()
> instead of sdhci_am654_setup_dll()
> - Change otap_del_sel[], itap_del_sel[], and itap_del_ena[]
> to type u32
> - Revert unnecessary reformating in sdhci_am654_set_clock()
> and sdhci_j721e_4bit_set_clock()
>
> Judith Mendez (7):
> mmc: sdhci_am654: Add tuning algorithm for delay chain
> mmc: sdhci_am654: Write ITAPDLY for DDR52 timing
> mmc: sdhci_am654: Add OTAP/ITAP delay enable
> mmc: sdhci_am654: Fix itapdly/otapdly array type
> mmc: sdhci_am654: Update comments in sdhci_am654_set_clock
> mmc: sdhci_am654: Add ITAPDLYSEL in sdhci_j721e_4bit_set_clock
> mmc: sdhci_am654: Fix ITAPDLY for HS400 timing
>
> drivers/mmc/host/sdhci_am654.c | 176 ++++++++++++++++++++++++++-------
> 1 file changed, 138 insertions(+), 38 deletions(-)
>

It's a bit unclear to me whether this series is actually fixing a
regression or whether it should be considered as improvements for the
tuning logic. For now, I decided that it looks like the latter (please
tell me if you don't agree). That said, the series is applied for
*next*, but I also took the liberty of re-ordering the patches, so
those without a fixes tag comes last.

Thanks and kind regards
Uffe