From: Ian Campbell <ijc@hellion.org.uk>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH v2 05/16] sunxi: dram: Remove broken impedance and ODT configuration code
Date: Tue, 05 Aug 2014 07:43:24 +0100 [thread overview]
Message-ID: <1407221004.23472.20.camel@dagon.hellion.org.uk> (raw)
In-Reply-To: <1407033174-24603-6-git-send-email-siarhei.siamashka@gmail.com>
On Sun, 2014-08-03 at 05:32 +0300, Siarhei Siamashka wrote:
> We can safely remove it, because none of the currently supported
> boards uses these features.
>
> The existing implementation had multiple problems:
> - unnecessary code duplication between sun4i/sun5i/sun7i
> - ZQ calibration was never initiated explicitly, and could be
> only triggered by setting the highest bit in the 'zq' parameter
> in the 'dram_para' struct (this was never actually done for
> any of the known Allwinner devices).
> - even if the ZQ calibration could be started, no attempts were
> made to wait for its completion, or checking whether the
> default automatically initiated ZQ calibration is still
> in progress
> - ODT was only ever enabled on sun4i, but not on sun5i/sun7i
>
> Additionally, SDR_IOCR was set to 0x00cc0000 only on sun4i. There
> are some hints in the Rockchip Linux kernel sources, indicating
> that these bits are related to the automatic I/O power down
> feature, which is poorly understood on sunxi hardware at the
> moment. Avoiding to set these bits on sun4i too does not seem to
> have any measurable/visible impact.
>
> The impedance and ODT configuration code will be re-introdeced in
> one of the next comits.
>
> Signed-off-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>
next prev parent reply other threads:[~2014-08-05 6:43 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-03 2:32 [U-Boot] [PATCH v2 00/16] sunxi: Allwinner A10/A13/A20 DRAM controller fixes Siarhei Siamashka
2014-08-03 2:32 ` [U-Boot] [PATCH v2 01/16] sunxi: dram: Remove useless 'dramc_scan_dll_para()' function Siarhei Siamashka
2014-08-03 2:32 ` [U-Boot] [PATCH v2 02/16] sunxi: dram: Remove broken super-standby remnants Siarhei Siamashka
2014-08-05 6:37 ` Ian Campbell
2014-08-03 2:32 ` [U-Boot] [PATCH v2 03/16] sunxi: dram: Respect the DDR3 reset timing requirements Siarhei Siamashka
2014-08-05 6:38 ` Ian Campbell
2014-08-03 2:32 ` [U-Boot] [PATCH v2 04/16] sunxi: dram: Fix CKE delay handling for sun4i/sun5i Siarhei Siamashka
2014-08-05 6:41 ` Ian Campbell
2014-08-03 2:32 ` [U-Boot] [PATCH v2 05/16] sunxi: dram: Remove broken impedance and ODT configuration code Siarhei Siamashka
2014-08-05 6:43 ` Ian Campbell [this message]
2014-08-03 2:32 ` [U-Boot] [PATCH v2 06/16] sunxi: dram: Do DDR3 reset in the same way on sun4i/sun5i/sun7i Siarhei Siamashka
2014-08-05 6:43 ` Ian Campbell
2014-08-03 2:32 ` [U-Boot] [PATCH v2 07/16] sunxi: dram: Add 'await_bits_clear'/'await_bits_set' helper functions Siarhei Siamashka
2014-08-05 6:44 ` Ian Campbell
2014-08-03 2:32 ` [U-Boot] [PATCH v2 08/16] sunxi: dram: Re-introduce the impedance calibration ond ODT Siarhei Siamashka
2014-08-05 6:47 ` Ian Campbell
2014-08-03 2:32 ` [U-Boot] [PATCH v2 09/16] sunxi: dram: Configurable MBUS clock speed (use PLL5 or PLL6) Siarhei Siamashka
2014-08-05 6:49 ` Ian Campbell
2014-08-03 2:32 ` [U-Boot] [PATCH v2 10/16] sunxi: dram: Use divisor P=1 for PLL5 Siarhei Siamashka
2014-08-03 2:32 ` [U-Boot] [PATCH v2 11/16] sunxi: dram: Improve DQS gate data training error handling Siarhei Siamashka
2014-08-03 2:32 ` [U-Boot] [PATCH v2 12/16] sunxi: dram: Add a helper function 'mctl_get_number_of_lanes' Siarhei Siamashka
2014-08-05 6:50 ` Ian Campbell
2014-08-03 2:32 ` [U-Boot] [PATCH v2 13/16] sunxi: dram: Configurable DQS gating window mode and delay Siarhei Siamashka
2014-08-05 6:53 ` Ian Campbell
2014-08-03 2:32 ` [U-Boot] [PATCH v2 14/16] sunxi: dram: Drop DDR2 support and assume only single rank DDR3 memory Siarhei Siamashka
2014-08-05 6:54 ` Ian Campbell
2014-08-03 2:32 ` [U-Boot] [PATCH v2 15/16] sunxi: dram: Derive write recovery delay from DRAM clock speed Siarhei Siamashka
2014-08-03 2:32 ` [U-Boot] [PATCH v2 16/16] sunxi: dram: Autodetect DDR3 bus width and density Siarhei Siamashka
2014-08-05 7:02 ` [U-Boot] [PATCH v2 00/16] sunxi: Allwinner A10/A13/A20 DRAM controller fixes Ian Campbell
2014-08-05 10:00 ` Hans de Goede
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