From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wi0-f182.google.com ([209.85.212.182]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YwauF-00023B-JN for linux-mtd@lists.infradead.org; Sun, 24 May 2015 18:45:57 +0000 Received: by wibt6 with SMTP id t6so31110279wib.0 for ; Sun, 24 May 2015 11:45:27 -0700 (PDT) Message-ID: <55621B83.4040909@vanguardiasur.com.ar> Date: Sun, 24 May 2015 15:42:11 -0300 From: Ezequiel Garcia MIME-Version: 1.0 To: Antoine Tenart Subject: Re: [PATCH v5 07/12] mtd: nand: add Samsung K9GBG08U0A-M to nand_ids table References: <1431356341-31640-1-git-send-email-antoine.tenart@free-electrons.com> <1431356341-31640-8-git-send-email-antoine.tenart@free-electrons.com> <555792FC.8030407@vanguardiasur.com.ar> <20150520140631.GN22054@kwain> <555C9584.1030609@vanguardiasur.com.ar> <20150520142409.GP22054@kwain> <20150520144341.GQ22054@kwain> In-Reply-To: <20150520144341.GQ22054@kwain> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: zmxu@marvell.com, boris.brezillon@free-electrons.com, Robert Jarzmik , linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, jszhang@marvell.com, computersforpeace@gmail.com, dwmw2@infradead.org, linux-arm-kernel@lists.infradead.org, sebastian.hesselbarth@gmail.com List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Antoine, On 05/20/2015 11:43 AM, Antoine Tenart wrote: [..] >> >> I just had a look on the datasheet, and I you're right, the nand should >> support JDEC. However I get a "No NAND device found" error when >> reverting this patch. >> >> It seems nand_flash_detect_jedec() is not reading "JDEC" and is returning >> directly. I'm having a look at this. > > So, I can read 'J', 'E', 'D' and 'E' but then I got 0xff's. So I tried > to only check of JEDE in nand_flash_detect_jedec() but the JEDEC > parameter page was then not valid. > This uncovers two different bugs in the driver. 1. read_id_bytes is either '2' or '4', but JEDEC detections needs at least 5 bytes. 2. The initial buffer (to read the ID and the parameter page) has 256 bytes, but the JEDEC parameter page is 512-bytes. And while at it, the driver doesn't seem to support reading the redundant parameter pages (recently reported on barebox ML [1]). So this is a third bug. Would you try setting read_id_bytes to '5' and also increasing the READ_PARAM transfer length? Something like this: diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c index 1259cc5..851372f 100644 --- a/drivers/mtd/nand/pxa3xx_nand.c +++ b/drivers/mtd/nand/pxa3xx_nand.c @@ -48,7 +48,7 @@ * STATUS, READID and PARAM. The largest of these is the PARAM command, * needing 256 bytes. */ -#define INIT_BUFFER_SIZE 256 +#define INIT_BUFFER_SIZE 2048 /* registers and bit definitions */ #define NDCR (0x00) /* Control register */ @@ -899,18 +899,18 @@ static int prepare_set_command(struct pxa3xx_nand_info *info, int command, break; case NAND_CMD_PARAM: - info->buf_count = 256; + info->buf_count = 2048; info->ndcb0 |= NDCB0_CMD_TYPE(0) | NDCB0_ADDR_CYC(1) | NDCB0_LEN_OVRD | command; info->ndcb1 = (column & 0xFF); - info->ndcb3 = 256; - info->data_size = 256; + info->ndcb3 = 2048; + info->data_size = 2048; break; [1] http://lists.infradead.org/pipermail/barebox/2015-May/023515.html Thanks, -- Ezequiel Garcia, VanguardiaSur www.vanguardiasur.com.ar