OMAP NAND driver support multiple ECC scheme, which can used in following different flavours, depending on in-build Hardware engines supported by SoC. +---------------------------------------+---------------+---------------+ | ECC scheme |ECC calculation|Error detection| +---------------------------------------+---------------+---------------+ |OMAP_ECC_HAM1_CODE_HW |H/W (GPMC) |S/W | +---------------------------------------+---------------+---------------+ |OMAP_ECC_BCH8_CODE_HW_DETECTION_SW |H/W (GPMC) |S/W | |(requires CONFIG_MTD_NAND_ECC_BCH) | | | +---------------------------------------+---------------+---------------+ |OMAP_ECC_BCH8_CODE_HW |H/W (GPMC) |H/W (ELM) | |(requires CONFIG_MTD_NAND_OMAP_BCH && | | | | ti,elm-id in DT) | | | +---------------------------------------+---------------+---------------+ To optimize footprint of omap2-nand driver, selection of some ECC schemes also require enabling following Kconfigs, in addition to setting appropriate DT bindings - Kconfig:CONFIG_MTD_NAND_ECC_BCH enables S/W based BCH ECC algorithm - Kconfig:CONFIG_MTD_NAND_OMAP_BCH enables H/W based BCH ECC algorithm This patch - removes OMAP_ECC_HAMMING_CODE_DEFAULT and OMAP_ECC_HAMMING_CODE_HW_ROMCODE - separates the configurations for other ECC schemes - fixes dependency issues based on Kconfig options - updates ELM device detection in is_elm_present() - cleans redundant code Signed-off-by: Pekon Gupta <pekon@xxxxxx> --- drivers/mtd/nand/omap2.c | 450 +++++++++++++++++++++++------------------------ 1 file changed, 220 insertions(+), 230 deletions(-) diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c index 8d521aa..fb96251 100644 --- a/drivers/mtd/nand/omap2.c +++ b/drivers/mtd/nand/omap2.c @@ -25,8 +25,10 @@ #include <linux/of.h> #include <linux/of_device.h> -#ifdef CONFIG_MTD_NAND_OMAP_BCH +#ifdef CONFIG_MTD_NAND_ECC_BCH #include <linux/bch.h> +#endif +#ifdef CONFIG_MTD_NAND_OMAP_BCH #include <linux/platform_data/elm.h> #endif @@ -141,6 +143,9 @@ #define BCH_ECC_SIZE0 0x0 /* ecc_size0 = 0, no oob protection */ #define BCH_ECC_SIZE1 0x20 /* ecc_size1 = 32 */ +#define BADBLOCK_MARKER_LENGTH 2 +#define OMAP_ECC_BCH8_POLYNOMIAL 0x201b + #ifdef CONFIG_MTD_NAND_OMAP_BCH static u_char bch8_vector[] = {0xf3, 0xdb, 0x14, 0x16, 0x8b, 0xd2, 0xbe, 0xcc, 0xac, 0x6b, 0xff, 0x99, 0x7b}; @@ -182,14 +187,11 @@ struct omap_nand_info { u_char *buf; int buf_len; struct gpmc_nand_regs reg; - -#ifdef CONFIG_MTD_NAND_OMAP_BCH - struct bch_control *bch; - struct nand_ecclayout ecclayout; + /* fields specific for BCHx_HW ECC scheme */ + struct bch_control *bch; bool is_elm_used; struct device *elm_dev; struct device_node *of_node; -#endif }; /** @@ -1058,8 +1060,7 @@ static int omap_dev_ready(struct mtd_info *mtd) } } -#ifdef CONFIG_MTD_NAND_OMAP_BCH - +#if defined(CONFIG_MTD_NAND_ECC_BCH) || defined(CONFIG_MTD_NAND_OMAP_BCH) /** * omap3_enable_hwecc_bch - Program OMAP3 GPMC to perform BCH ECC correction * @mtd: MTD device structure @@ -1140,7 +1141,9 @@ static void omap3_enable_hwecc_bch(struct mtd_info *mtd, int mode) /* Clear ecc and enable bits */ writel(ECCCLEAR | ECC1, info->reg.gpmc_ecc_control); } +#endif +#ifdef CONFIG_MTD_NAND_ECC_BCH /** * omap3_calculate_ecc_bch4 - Generate 7 bytes of ECC bytes * @mtd: MTD device structure @@ -1225,7 +1228,9 @@ static int omap3_calculate_ecc_bch8(struct mtd_info *mtd, const u_char *dat, return 0; } +#endif /* CONFIG_MTD_NAND_ECC_BCH */ +#ifdef CONFIG_MTD_NAND_OMAP_BCH /** * omap3_calculate_ecc_bch - Generate bytes of ECC bytes * @mtd: MTD device structure @@ -1517,7 +1522,9 @@ static int omap_elm_correct_data(struct mtd_info *mtd, u_char *data, return stat; } +#endif /* CONFIG_MTD_NAND_OMAP_BCH */ +#ifdef CONFIG_MTD_NAND_ECC_BCH /** * omap3_correct_data_bch - Decode received data and correct errors * @mtd: MTD device structure @@ -1549,7 +1556,9 @@ static int omap3_correct_data_bch(struct mtd_info *mtd, u_char *data, } return count; } +#endif /* CONFIG_MTD_NAND_ECC_BCH */ +#ifdef CONFIG_MTD_NAND_OMAP_BCH /** * omap_write_page_bch - BCH ecc based write page function for entire page * @mtd: mtd info structure @@ -1637,197 +1646,68 @@ static int omap_read_page_bch(struct mtd_info *mtd, struct nand_chip *chip, } /** - * omap3_free_bch - Release BCH ecc resources - * @mtd: MTD device structure + * is_elm_present - checks for presence of ELM module by scanning DT nodes + * @omap_nand_info: NAND device structure containing platform data + * @bch_type: 0x0=BCH4, 0x1=BCH8, 0x2=BCH16 */ -static void omap3_free_bch(struct mtd_info *mtd) +static int is_elm_present(struct omap_nand_info *info, + struct device_node *elm_node, enum bch_ecc bch_type) { - struct omap_nand_info *info = container_of(mtd, struct omap_nand_info, - mtd); - if (info->bch) { - free_bch(info->bch); - info->bch = NULL; - } -} - -/** - * omap3_init_bch - Initialize BCH ECC - * @mtd: MTD device structure - * @ecc_opt: OMAP ECC mode (OMAP_ECC_BCH4_CODE_HW or OMAP_ECC_BCH8_CODE_HW) - */ -static int omap3_init_bch(struct mtd_info *mtd, int ecc_opt) -{ - int max_errors; - struct omap_nand_info *info = container_of(mtd, struct omap_nand_info, - mtd); -#ifdef CONFIG_MTD_NAND_OMAP_BCH8 - const int hw_errors = BCH8_MAX_ERROR; -#else - const int hw_errors = BCH4_MAX_ERROR; -#endif - enum bch_ecc bch_type; - const __be32 *parp; - int lenp; - struct device_node *elm_node; - - info->bch = NULL; - - max_errors = (ecc_opt == OMAP_ECC_BCH8_CODE_HW) ? - BCH8_MAX_ERROR : BCH4_MAX_ERROR; - if (max_errors != hw_errors) { - pr_err("cannot configure %d-bit BCH ecc, only %d-bit supported", - max_errors, hw_errors); - goto fail; - } - - info->nand.ecc.size = 512; - info->nand.ecc.hwctl = omap3_enable_hwecc_bch; - info->nand.ecc.mode = NAND_ECC_HW; - info->nand.ecc.strength = max_errors; - - if (hw_errors == BCH8_MAX_ERROR) - bch_type = BCH8_ECC; - else - bch_type = BCH4_ECC; - - /* Detect availability of ELM module */ - parp = of_get_property(info->of_node, "elm_id", &lenp); - if ((parp == NULL) && (lenp != (sizeof(void *) * 2))) { - pr_err("Missing elm_id property, fall back to Software BCH\n"); - info->is_elm_used = false; - } else { - struct platform_device *pdev; - - elm_node = of_find_node_by_phandle(be32_to_cpup(parp)); - pdev = of_find_device_by_node(elm_node); - info->elm_dev = &pdev->dev; - - if (elm_config(info->elm_dev, bch_type) == 0) - info->is_elm_used = true; + struct platform_device *pdev; + info->is_elm_used = false; + /* check whether elm-id is passed via DT */ + if (!elm_node) { + pr_err("nand: error: ELM DT node not found\n"); + return -ENODEV; } - - if (info->is_elm_used && (mtd->writesize <= 4096)) { - - if (hw_errors == BCH8_MAX_ERROR) - info->nand.ecc.bytes = BCH8_SIZE; - else - info->nand.ecc.bytes = BCH4_SIZE; - - info->nand.ecc.correct = omap_elm_correct_data; - info->nand.ecc.calculate = omap3_calculate_ecc_bch; - info->nand.ecc.read_page = omap_read_page_bch; - info->nand.ecc.write_page = omap_write_page_bch; - } else { - /* - * software bch library is only used to detect and - * locate errors - */ - info->bch = init_bch(13, max_errors, - 0x201b /* hw polynomial */); - if (!info->bch) - goto fail; - - info->nand.ecc.correct = omap3_correct_data_bch; - - /* - * The number of corrected errors in an ecc block that will - * trigger block scrubbing defaults to the ecc strength (4 or 8) - * Set mtd->bitflip_threshold here to define a custom threshold. - */ - - if (max_errors == 8) { - info->nand.ecc.bytes = 13; - info->nand.ecc.calculate = omap3_calculate_ecc_bch8; - } else { - info->nand.ecc.bytes = 7; - info->nand.ecc.calculate = omap3_calculate_ecc_bch4; - } + pdev = of_find_device_by_node(elm_node); + /* check whether ELM device is registered */ + if (!pdev) { + pr_err("nand: error: ELM device not found\n"); + return -ENODEV; } - - pr_info("enabling NAND BCH ecc with %d-bit correction\n", max_errors); + /* ELM module available, now configure it */ + info->elm_dev = &pdev->dev; + if (elm_config(info->elm_dev, bch_type)) + return -ENODEV; + info->is_elm_used = true; return 0; -fail: - omap3_free_bch(mtd); - return -1; } +#endif /* CONFIG_MTD_NAND_ECC_BCH */ +#ifdef CONFIG_MTD_NAND_ECC_BCH /** - * omap3_init_bch_tail - Build an oob layout for BCH ECC correction. + * omap3_free_bch - Release BCH ecc resources * @mtd: MTD device structure */ -static int omap3_init_bch_tail(struct mtd_info *mtd) +static void omap3_free_bch(struct mtd_info *mtd) { - int i, steps, offset; struct omap_nand_info *info = container_of(mtd, struct omap_nand_info, mtd); - struct nand_ecclayout *layout = &info->ecclayout; - - /* build oob layout */ - steps = mtd->writesize/info->nand.ecc.size; - layout->eccbytes = steps*info->nand.ecc.bytes; - - /* do not bother creating special oob layouts for small page devices */ - if (mtd->oobsize < 64) { - pr_err("BCH ecc is not supported on small page devices\n"); - goto fail; - } - - /* reserve 2 bytes for bad block marker */ - if (layout->eccbytes+2 > mtd->oobsize) { - pr_err("no oob layout available for oobsize %d eccbytes %u\n", - mtd->oobsize, layout->eccbytes); - goto fail; + if (info->bch) { + free_bch(info->bch); + info->bch = NULL; } - - /* ECC layout compatible with RBL for BCH8 */ - if (info->is_elm_used && (info->nand.ecc.bytes == BCH8_SIZE)) - offset = 2; - else - offset = mtd->oobsize - layout->eccbytes; - - /* put ecc bytes at oob tail */ - for (i = 0; i < layout->eccbytes; i++) - layout->eccpos[i] = offset + i; - - if (info->is_elm_used && (info->nand.ecc.bytes == BCH8_SIZE)) - layout->oobfree[0].offset = 2 + layout->eccbytes * steps; - else - layout->oobfree[0].offset = 2; - - layout->oobfree[0].length = mtd->oobsize-2-layout->eccbytes; - info->nand.ecc.layout = layout; - - if (!(info->nand.options & NAND_BUSWIDTH_16)) - info->nand.badblock_pattern = &bb_descrip_flashbased; - return 0; -fail: - omap3_free_bch(mtd); - return -1; } #else -static int omap3_init_bch(struct mtd_info *mtd, int ecc_opt) -{ - pr_err("CONFIG_MTD_NAND_OMAP_BCH is not enabled\n"); - return -1; -} -static int omap3_init_bch_tail(struct mtd_info *mtd) -{ - return -1; -} + static void omap3_free_bch(struct mtd_info *mtd) { } -#endif /* CONFIG_MTD_NAND_OMAP_BCH */ +#endif /* CONFIG_MTD_NAND_ECC_BCH */ static int omap_nand_probe(struct platform_device *pdev) { struct omap_nand_info *info; struct omap_nand_platform_data *pdata; + struct mtd_info *mtd; + struct nand_chip *nand_chip; + struct nand_ecclayout *ecclayout; int err; - int i, offset; - dma_cap_mask_t mask; - unsigned sig; + int i; + dma_cap_mask_t mask; + unsigned sig; struct resource *res; struct mtd_part_parser_data ppdata = {}; @@ -1846,20 +1726,18 @@ static int omap_nand_probe(struct platform_device *pdev) spin_lock_init(&info->controller.lock); init_waitqueue_head(&info->controller.wq); - info->pdev = pdev; - + mtd = &info->mtd; + mtd->name = dev_name(&pdev->dev); + mtd->owner = THIS_MODULE; + mtd->priv = &info->nand; + nand_chip = &info->nand; + info->pdev = pdev; info->gpmc_cs = pdata->cs; info->reg = pdata->reg; + info->bch = NULL; - info->mtd.priv = &info->nand; - info->mtd.name = dev_name(&pdev->dev); - info->mtd.owner = THIS_MODULE; - - info->nand.options = pdata->devsize; - info->nand.options |= NAND_SKIP_BBTSCAN; -#ifdef CONFIG_MTD_NAND_OMAP_BCH + nand_chip->options |= NAND_SKIP_BBTSCAN | NAND_BUSWIDTH_AUTO; info->of_node = pdata->of_node; -#endif res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (res == NULL) { @@ -1903,6 +1781,30 @@ static int omap_nand_probe(struct platform_device *pdev) info->nand.chip_delay = 50; } + /* scan NAND device conncted to controller */ + if (nand_scan_ident(mtd, 1, NULL)) { + err = -ENXIO; + goto out_release_mem_region; + } + pr_info("%s: detected %s NAND flash\n", DRIVER_NAME, + (nand_chip->options & NAND_BUSWIDTH_16) ? "x16" : "x8"); + if ((nand_chip->options & NAND_BUSWIDTH_16) != + (pdata->devsize & NAND_BUSWIDTH_16)) { + pr_err("%s: but incorrectly configured as %s", DRIVER_NAME, + (pdata->devsize & NAND_BUSWIDTH_16) ? "x16" : "x8"); + err = -EINVAL; + goto out_release_mem_region; + } + + /* check for small page devices */ + if ((mtd->oobsize < 64) && + (pdata->ecc_opt != OMAP_ECC_HAM1_CODE_HW)) { + pr_err("small page devices are not supported\n"); + err = -EINVAL; + goto out_release_mem_region; + } + + /* populate read & write API based on xfer_type selected */ switch (pdata->xfer_type) { case NAND_OMAP_PREFETCH_POLLED: info->nand.read_buf = omap_read_buf_pref; @@ -1992,61 +1894,148 @@ static int omap_nand_probe(struct platform_device *pdev) goto out_release_mem_region; } - /* select the ecc type */ - if (pdata->ecc_opt == OMAP_ECC_HAM1_CODE_HW) { - info->nand.ecc.bytes = 3; - info->nand.ecc.size = 512; - info->nand.ecc.strength = 1; - info->nand.ecc.calculate = omap_calculate_ecc; - info->nand.ecc.hwctl = omap_enable_hwecc; - info->nand.ecc.correct = omap_correct_data; - info->nand.ecc.mode = NAND_ECC_HW; - } else if ((pdata->ecc_opt == OMAP_ECC_BCH4_CODE_HW) || - (pdata->ecc_opt == OMAP_ECC_BCH8_CODE_HW)) { - err = omap3_init_bch(&info->mtd, pdata->ecc_opt); - if (err) { + /* populate MTD interface based on ECC scheme */ + nand_chip->ecc.layout = &omap_oobinfo; + ecclayout = &omap_oobinfo; + switch (pdata->ecc_opt) { + case OMAP_ECC_HAM1_CODE_HW: + pr_info("nand: using OMAP_ECC_HAM1_CODE_HW\n"); + nand_chip->ecc.mode = NAND_ECC_HW; + nand_chip->ecc.bytes = 3; + nand_chip->ecc.size = 512; + nand_chip->ecc.strength = 1; + nand_chip->ecc.calculate = omap_calculate_ecc; + nand_chip->ecc.hwctl = omap_enable_hwecc; + nand_chip->ecc.correct = omap_correct_data; + /* define custom ECC layout */ + ecclayout->eccbytes = nand_chip->ecc.bytes * + (mtd->writesize / + nand_chip->ecc.size); + if (nand_chip->options & NAND_BUSWIDTH_16) + ecclayout->eccpos[0] = BADBLOCK_MARKER_LENGTH; + else + ecclayout->eccpos[0] = 1; + ecclayout->oobfree->offset = ecclayout->eccpos[0] + + ecclayout->eccbytes; + break; + + case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW: +#ifdef CONFIG_MTD_NAND_ECC_BCH + pr_info("nand: using OMAP_ECC_BCH4_CODE_HW_DETECTION_SW\n"); + nand_chip->ecc.mode = NAND_ECC_HW; + nand_chip->ecc.size = 512; + nand_chip->ecc.bytes = 7; + nand_chip->ecc.strength = 4; + nand_chip->ecc.hwctl = omap3_enable_hwecc_bch; + nand_chip->ecc.correct = omap3_correct_data_bch; + nand_chip->ecc.calculate = omap3_calculate_ecc_bch4; + /* define custom ECC layout */ + ecclayout->eccbytes = nand_chip->ecc.bytes * + (mtd->writesize / + nand_chip->ecc.size); + ecclayout->eccpos[0] = BADBLOCK_MARKER_LENGTH; + ecclayout->oobfree->offset = ecclayout->eccpos[0] + + ecclayout->eccbytes; + /* software bch library is used for locating errors */ + info->bch = init_bch(nand_chip->ecc.bytes, + nand_chip->ecc.strength, + OMAP_ECC_BCH8_POLYNOMIAL); + if (!info->bch) { + pr_err("nand: error: unable to use s/w BCH library\n"); err = -EINVAL; - goto out_release_mem_region; } - } + break; +#else + pr_err("nand: error: CONFIG_MTD_NAND_ECC_BCH not enabled\n"); + err = -EINVAL; + goto out_release_mem_region; +#endif - /* DIP switches on some boards change between 8 and 16 bit - * bus widths for flash. Try the other width if the first try fails. - */ - if (nand_scan_ident(&info->mtd, 1, NULL)) { - info->nand.options ^= NAND_BUSWIDTH_16; - if (nand_scan_ident(&info->mtd, 1, NULL)) { - err = -ENXIO; + case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW: +#ifdef CONFIG_MTD_NAND_ECC_BCH + pr_info("nand: using OMAP_ECC_BCH8_CODE_HW_DETECTION_SW\n"); + nand_chip->ecc.mode = NAND_ECC_HW; + nand_chip->ecc.size = 512; + nand_chip->ecc.bytes = 13; + nand_chip->ecc.strength = 8; + nand_chip->ecc.hwctl = omap3_enable_hwecc_bch; + nand_chip->ecc.correct = omap3_correct_data_bch; + nand_chip->ecc.calculate = omap3_calculate_ecc_bch8; + /* define custom ECC layout */ + ecclayout->eccbytes = nand_chip->ecc.bytes * + (mtd->writesize / + nand_chip->ecc.size); + ecclayout->eccpos[0] = BADBLOCK_MARKER_LENGTH; + ecclayout->oobfree->offset = ecclayout->eccpos[0] + + ecclayout->eccbytes; + /* software bch library is used for locating errors */ + info->bch = init_bch(nand_chip->ecc.bytes, + nand_chip->ecc.strength, + OMAP_ECC_BCH8_POLYNOMIAL); + if (!info->bch) { + pr_err("nand: error: unable to use s/w BCH library\n"); + err = -EINVAL; goto out_release_mem_region; } - } - - /* rom code layout */ - if (pdata->ecc_opt == OMAP_ECC_HAM1_CODE_HW) { + break; +#else + pr_err("nand: error: CONFIG_MTD_NAND_ECC_BCH not enabled\n"); + err = -EINVAL; + goto out_release_mem_region; +#endif - if (info->nand.options & NAND_BUSWIDTH_16) - offset = 2; - else { - offset = 1; - info->nand.badblock_pattern = &bb_descrip_flashbased; - } - omap_oobinfo.eccbytes = 3 * (info->mtd.writesize / 512); - for (i = 0; i < omap_oobinfo.eccbytes; i++) - omap_oobinfo.eccpos[i] = i+offset; - - omap_oobinfo.oobfree->offset = offset + omap_oobinfo.eccbytes; - omap_oobinfo.oobfree->length = info->mtd.oobsize - - (offset + omap_oobinfo.eccbytes); - - info->nand.ecc.layout = &omap_oobinfo; - } else if ((pdata->ecc_opt == OMAP_ECC_BCH4_CODE_HW) || - (pdata->ecc_opt == OMAP_ECC_BCH8_CODE_HW)) { - /* build OOB layout for BCH ECC correction */ - err = omap3_init_bch_tail(&info->mtd); - if (err) { - err = -EINVAL; + case OMAP_ECC_BCH8_CODE_HW: +#ifdef CONFIG_MTD_NAND_OMAP_BCH + pr_info("nand: using OMAP_ECC_BCH8_CODE_HW ECC scheme\n"); + nand_chip->ecc.mode = NAND_ECC_HW; + nand_chip->ecc.size = 512; + /* 14th bit is kept reserved for ROM-code compatibility */ + nand_chip->ecc.bytes = 13 + 1; + nand_chip->ecc.strength = 8; + nand_chip->ecc.hwctl = omap3_enable_hwecc_bch; + nand_chip->ecc.correct = omap_elm_correct_data; + nand_chip->ecc.calculate = omap3_calculate_ecc_bch; + nand_chip->ecc.read_page = omap_read_page_bch; + nand_chip->ecc.write_page = omap_write_page_bch; + /* This ECC scheme requires ELM H/W block */ + if (is_elm_present(info, pdata->elm_of_node, BCH8_ECC) < 0) { + pr_err("nand: error: could not initialize ELM\n"); goto out_release_mem_region; } + /* define custom ECC layout */ + ecclayout->eccbytes = nand_chip->ecc.bytes * + (mtd->writesize / + nand_chip->ecc.size); + ecclayout->eccpos[0] = BADBLOCK_MARKER_LENGTH; + ecclayout->oobfree->offset = ecclayout->eccpos[0] + + ecclayout->eccbytes; + break; +#else + pr_err("nand: error: CONFIG_MTD_NAND_OMAP_BCH not enabled\n"); + err = -EINVAL; + goto out_release_mem_region; +#endif + + default: + pr_err("nand: error: invalid or unsupported ECC scheme\n"); + err = -EINVAL; + goto out_release_mem_region; + } + + /* populate remaining info for custom ecc layout */ + pr_info("%s: using custom ecc layout\n", DRIVER_NAME); + ecclayout->oobfree->length = mtd->oobsize - BADBLOCK_MARKER_LENGTH + - ecclayout->eccbytes; + if (!(nand_chip->options & NAND_BUSWIDTH_16)) + nand_chip->badblock_pattern = &bb_descrip_flashbased; + for (i = 1; i < ecclayout->eccbytes; i++) + ecclayout->eccpos[i] = ecclayout->eccpos[0] + i; + /* check if NAND OOBSIZE meets ECC scheme requirement */ + if (mtd->oobsize < (ecclayout->eccbytes + BADBLOCK_MARKER_LENGTH)) { + pr_err("not enough OOB bytes required = %d, available=%d\n", + ecclayout->eccbytes, mtd->oobsize); + err = -EINVAL; + goto out_release_mem_region; } /* second phase scan */ @@ -2072,6 +2061,7 @@ out_release_mem_region: free_irq(info->gpmc_irq_fifo, info); release_mem_region(info->phys_base, info->mem_size); out_free_info: + omap3_free_bch(&info->mtd); kfree(info); return err; -- 1.8.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html