From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wg0-x232.google.com ([2a00:1450:400c:c00::232]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XIkQj-0005au-SJ for linux-mtd@lists.infradead.org; Sat, 16 Aug 2014 20:18:26 +0000 Received: by mail-wg0-f50.google.com with SMTP id n12so3450635wgh.33 for ; Sat, 16 Aug 2014 13:18:02 -0700 (PDT) From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= To: linux-mtd@lists.infradead.org, David Woodhouse , Artem Bityutskiy , Brian Norris Subject: [PATCH] mtd: spi-nor: add Kconfig option to disable 4K sectors Date: Sat, 16 Aug 2014 22:17:51 +0200 Message-Id: <1408220271-21455-1-git-send-email-zajec5@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Current situation with 4K sectors is quite messy. First of all, some MTD "users" don't work with such small size. An example may be UBIFS which requires 15 KiB erase blocks as a minimum. In theory spi-nor should provide multiple erase regions and MTD "users" should use the one they need. Unforunately that is not implemented. In the result our flashes database in spi-nor is hackish. For some flashes we pretend they don't support 4K sectors just because some distribution users UBIFS on it. This ofc leads to conflicts, like Samsung using w25q128 with 4K sectors vs. OpenWrt requiring it to pretend it's 64 KiB blocks only. My idea (plan?) for fixing this situation: 1) Use real hw info (this requires a way for disabling 4K for now) 2) Provide detailed info about erase regions 3) Make UBIFS work with devices that support 4K sectors Signed-off-by: Rafał Miłecki --- drivers/mtd/spi-nor/Kconfig | 11 +++++++++++ drivers/mtd/spi-nor/spi-nor.c | 5 ++++- 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/drivers/mtd/spi-nor/Kconfig b/drivers/mtd/spi-nor/Kconfig index f8acfa4..601879e 100644 --- a/drivers/mtd/spi-nor/Kconfig +++ b/drivers/mtd/spi-nor/Kconfig @@ -7,6 +7,17 @@ menuconfig MTD_SPI_NOR if MTD_SPI_NOR +config MTD_SPI_NOR_USE_4K_SECTORS + bool "Use small 4096 B erase sectors" + default y + help + Many flash memories support erasing small (4096 B) sectors. Depending + on the usage this feature may provide performance gain in comparison + to erasing whole blocks (32/64 KiB). + + Please note that some tools/drivers/filesystems may not work with + 4096 B erase size (e.g. UBIFS requires 15 KiB as a minimum). + config SPI_FSL_QUADSPI tristate "Freescale Quad SPI controller" depends on ARCH_MXC diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c index ba3f61e..ae16aa2 100644 --- a/drivers/mtd/spi-nor/spi-nor.c +++ b/drivers/mtd/spi-nor/spi-nor.c @@ -987,6 +987,7 @@ int spi_nor_scan(struct spi_nor *nor, const struct spi_device_id *id, nor->wait_till_ready == spi_nor_wait_till_ready) nor->wait_till_ready = spi_nor_wait_till_fsr_ready; +#ifdef CONFIG_MTD_SPI_NOR_USE_4K_SECTORS /* prefer "small sector" erase if possible */ if (info->flags & SECT_4K) { nor->erase_opcode = SPINOR_OP_BE_4K; @@ -994,7 +995,9 @@ int spi_nor_scan(struct spi_nor *nor, const struct spi_device_id *id, } else if (info->flags & SECT_4K_PMC) { nor->erase_opcode = SPINOR_OP_BE_4K_PMC; mtd->erasesize = 4096; - } else { + } else +#endif + { nor->erase_opcode = SPINOR_OP_SE; mtd->erasesize = info->sector_size; } -- 1.8.4.5