This patch set is meant for as a review for comments, and is the result of the discussion on MMC quirks. Sorry ahead of time if I didn't format this correctly. It's my first tiem with git mail-send :-).
For 1/3: Arnd suggested setting the default write alignment to adjust on to be 32K. Since I don't have conclusive data and I don't have a large set of flash memory to test on, the default behavior is "do nothing", i.e. only quirk 3/3 sets the parameter to 8K as per manufacturer suggestion. Table of Contents: [RFC 1/3] MMC: Adjust unaligned write accesses. [RFC 2/3] MMC: Add block quirks support. [RFC 3/3] MMC: Toshiba eMMC - Split 8K-unaligned accesses. Here is an example of the effects of 3/3 on the Toshiba MMC32G card. Before - /data/flashbench -A -b 1024 /dev/block/platform/sdhci-tegra.3/by-name/cache write align 8388608 pre 3.84ms on 7.45ms post 4.32ms diff 3.37ms write align 4194304 pre 3.53ms on 6.43ms post 3.28ms diff 3.02ms write align 2097152 pre 4.1ms on 7.19ms post 3.99ms diff 3.14ms write align 1048576 pre 4.2ms on 7.54ms post 4.38ms diff 3.26ms write align 524288 pre 4.19ms on 7.37ms post 4.37ms diff 3.1ms write align 262144 pre 4.2ms on 7.52ms post 4.38ms diff 3.23ms write align 131072 pre 4.19ms on 7.48ms post 4.38ms diff 3.2ms write align 65536 pre 4.19ms on 7.38ms post 4.38ms diff 3.1ms write align 32768 pre 4.17ms on 7.44ms post 4.37ms diff 3.17ms write align 16384 pre 3.67ms on 146ms post 3.55ms diff 143ms write align 8192 pre 3.63ms on 137ms post 3.54ms diff 134ms write align 4096 pre 4.35ms on 4.42ms post 4.24ms diff 121µs write align 2048 pre 4.4ms on 4.18ms post 4.43ms diff -235734 8KB write alignment - /data/flashbench -A -b 1024 /dev/block/platform/sdhci-tegra.3/by-name/cache write align 8388608 pre 3.22ms on 6.48ms post 3.24ms diff 3.25ms write align 4194304 pre 3.43ms on 6.67ms post 3.4ms diff 3.25ms write align 2097152 pre 3.54ms on 6.81ms post 3.35ms diff 3.37ms write align 1048576 pre 3.68ms on 6.77ms post 3.57ms diff 3.14ms write align 524288 pre 3.64ms on 6.9ms post 3.66ms diff 3.25ms write align 262144 pre 3.65ms on 6.9ms post 3.33ms diff 3.41ms write align 131072 pre 3.64ms on 6.9ms post 3.68ms diff 3.24ms write align 65536 pre 3.65ms on 6.89ms post 3.4ms diff 3.37ms write align 32768 pre 3.39ms on 6.78ms post 3.67ms diff 3.25ms write align 16384 pre 3.67ms on 6.89ms post 3.67ms diff 3.22ms write align 8192 pre 3.68ms on 6.89ms post 3.66ms diff 3.22ms write align 4096 pre 3.74ms on 3.73ms post 3.73ms diff -4281ns write align 2048 pre 3.73ms on 3.73ms post 3.73ms diff 2.59µs -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
