From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932401AbaIWPEq (ORCPT ); Tue, 23 Sep 2014 11:04:46 -0400 Received: from mail-pa0-f46.google.com ([209.85.220.46]:51039 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932109AbaIWPEo (ORCPT ); Tue, 23 Sep 2014 11:04:44 -0400 Date: Tue, 23 Sep 2014 23:04:28 +0800 From: Huang Shijie To: Boris BREZILLON Cc: David Woodhouse , Brian Norris , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Mike Voytovich , Roy Lee Subject: Re: [PATCH v3 1/3] mtd: nand: gpmi: add gpmi_move_bits function Message-ID: <20140923150427.GB1633@localhost.localdomain> References: <1411481256-29141-1-git-send-email-boris.brezillon@free-electrons.com> <1411481256-29141-2-git-send-email-boris.brezillon@free-electrons.com> <20140923145413.GA1633@localhost.localdomain> <20140923165822.27cfde69@bbrezillon> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140923165822.27cfde69@bbrezillon> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 23, 2014 at 04:58:22PM +0200, Boris BREZILLON wrote: > On Tue, 23 Sep 2014 22:54:15 +0800 > Huang Shijie wrote: > > > On Tue, Sep 23, 2014 at 04:07:34PM +0200, Boris BREZILLON wrote: > > > Add a new function to move bits (not bytes) from a memory region to > > > another one. > > > This function is similar to memmove except it acts at bit level. > > > This function is needed to implement GPMI raw access functions, given the > > > fact that ECC engine does not pad ECC bits to the next byte boundary. > > sorry for not comment your v2 patch set. > > > > > > > > Signed-off-by: Boris BREZILLON > > > --- > > > drivers/mtd/nand/gpmi-nand/gpmi-lib.c | 88 ++++++++++++++++++++++++++++++++++ > > > drivers/mtd/nand/gpmi-nand/gpmi-nand.h | 4 ++ > > > 2 files changed, 92 insertions(+) > > > > > > diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-lib.c b/drivers/mtd/nand/gpmi-nand/gpmi-lib.c > > > index 87e658c..e2f706a 100644 > > > --- a/drivers/mtd/nand/gpmi-nand/gpmi-lib.c > > > +++ b/drivers/mtd/nand/gpmi-nand/gpmi-lib.c > > > @@ -1353,3 +1353,91 @@ int gpmi_read_page(struct gpmi_nand_data *this, > > > set_dma_type(this, DMA_FOR_READ_ECC_PAGE); > > > return start_dma_with_bch_irq(this, desc); > > > } > > > + > > > +void gpmi_move_bits(u8 *dst, size_t dst_bit_off, > > > + const u8 *src, size_t src_bit_off, > > > + size_t nbits) > > we can simplify the code. > > Any suggestions ? > > > > > We could use the bytes to replace the @nbits. > > > > The chunk data is always byte aligned. > > This function is also used to store ECC bits in the OOB buffer and > these chunk of data are not byte aligned :-). yes. you are right. I missed it. could you also comment these two hooks in the patch set. I hope Brian also can check it, and we can make it more clear about how to implement them. thanks Huang Shijie