From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.bootlin.com ([62.4.15.54]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1fqdVs-0001W5-Hx for linux-mtd@lists.infradead.org; Fri, 17 Aug 2018 12:05:58 +0000 Date: Fri, 17 Aug 2018 14:05:43 +0200 From: Boris Brezillon To: Prabhakar Kushwaha Cc: "linux-mtd@lists.infradead.org" Subject: Re: NOR access from ARM-BE toolchain Message-ID: <20180817140543.44ec1337@bbrezillon> In-Reply-To: References: 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 Fri, 17 Aug 2018 10:54:24 +0000 Prabhakar Kushwaha wrote: > Hi Boris, > > I am trying to access NOR flash with ARM running in big-endian mode. But it is causing error as " do_map_probe() failed for type cfi_probe" > > On our platform, The connection between Flash controller and NOR flash is little-endian. > Here, ARM core running in littler endian mode with MTD_CFI_NOSWAP every things work fine. > > if we change ARM mode as big-endian, it start showing error as mentioned above. > Error is same even with MTD_CFI_BE_BYTE_SWAP option. > As per my understanding MTD_CFI_BE_BYTE_SWAP or MTD_CFI_LE_BYTE_SWAP deals with flash controller and flash connection. If it works in little endian, you should enable MTD_CFI_LE_BYTE_SWAP (or add the little-endian prop to the flash node in your DT). > Not sure, if take care of Core endianness also. > > Please suggest!! > > Regards, > Prabhakar >