From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.bootlin.com ([62.4.15.54]) by casper.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gMva4-0001L9-MT for linux-mtd@lists.infradead.org; Wed, 14 Nov 2018 13:51:46 +0000 Date: Wed, 14 Nov 2018 14:51:29 +0100 From: Boris Brezillon To: Liu Xiang Cc: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, marek.vasut@gmail.com, dwmw2@infradead.org, computersforpeace@gmail.com, richard@nod.at, liuxiang_1999@126.com, Tudor Ambarus Subject: Re: [PATCH] mtd: spi-nor: Return error when nor->addr_width not match the device size Message-ID: <20181114145129.568e4bb3@bbrezillon> In-Reply-To: <1542200165-3073-1-git-send-email-liu.xiang6@zte.com.cn> References: <1542200165-3073-1-git-send-email-liu.xiang6@zte.com.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 14 Nov 2018 20:56:05 +0800 Liu Xiang wrote: > In is25lp256, the DWORD1 of JEDEC Basic Flash Parameter Header > is 0xfff920e5. So the DWORD1[18:17] Address Bytes bits are 0b00, > means that 3-Byte only addressing. According to your other patch this NOR supports 4B opcode, which means the SFDP table is wrong. > But the device size is larger > than 16MB, nor->addr_width must be 4 to access the whole address. > An error should be returned when nor->addr_width not match ^does not > the device size in spi_nor_parse_sfdp(). > > Suggested-by: Boris Brezillon > Signed-off-by: Liu Xiang > --- > drivers/mtd/spi-nor/spi-nor.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c > index 3eba13a..77eaf22 100644 > --- a/drivers/mtd/spi-nor/spi-nor.c > +++ b/drivers/mtd/spi-nor/spi-nor.c > @@ -2669,6 +2669,10 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor, > } > params->size >>= 3; /* Convert to bytes. */ > > + /*if the device exceeds 16MiB, addr_width must be 4*/ Please add a white space after '/*' and before '*/': /* If the device exceeds 16MiB, ->addr_width must be 4. */ > + if ((params->size > 0x1000000) && (nor->addr_width == 3)) Parens are not needed around sub-conditions: if (params->size > 0x1000000 && nor->addr_width == 3) > + return -EINVAL; > + I'm not sure this is correct. Looks like some NORs only support 3B opcodes but have a "4-byte addressing" mode (see set_4byte() [1]). Don't know what's reported by the BFPT section in this case though (BFPT_DWORD1_ADDRESS_BYTES_3_ONLY or BFPT_DWORD1_ADDRESS_BYTES_3_OR_4). Anyway, I think this check should be moved here [2] to cover the non-SFDP case. > /* Fast Read settings. */ > for (i = 0; i < ARRAY_SIZE(sfdp_bfpt_reads); i++) { > const struct sfdp_bfpt_read *rd = &sfdp_bfpt_reads[i]; [1]https://elixir.bootlin.com/linux/v4.20-rc2/source/drivers/mtd/spi-nor/spi-nor.c#L278 [2]https://elixir.bootlin.com/linux/v4.20-rc2/source/drivers/mtd/spi-nor/spi-nor.c#L3758