From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Date: Fri, 12 Dec 2014 13:58:29 +0100 Subject: [U-Boot] [PATCH] mtd: nand: mxs: fix PIO_WORD number In-Reply-To: <548AE2EA.7030308@denx.de> References: <1418199884-2430-1-git-send-email-luca.ellero@brickedbrain.com> <548AE228.7040806@brickedbrain.com> <548AE2EA.7030308@denx.de> Message-ID: <201412121358.29505.marex@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Friday, December 12, 2014 at 01:43:22 PM, Stefan Roese wrote: > Hi Luca, > > On 12.12.2014 13:40, Luca Ellero wrote: > >> On 10.12.2014 09:24, Luca Ellero wrote: > >>> There is only one pio_word in this DMA transaction so data field must > >>> be 1. > >>> > >>> Signed-off-by: Luca Ellero > >>> --- > >>> > >>> drivers/mtd/nand/mxs_nand.c | 2 +- > >>> 1 file changed, 1 insertion(+), 1 deletion(-) > >>> > >>> diff --git a/drivers/mtd/nand/mxs_nand.c b/drivers/mtd/nand/mxs_nand.c > >>> index 7a064ab..616c9ca 100644 > >>> --- a/drivers/mtd/nand/mxs_nand.c > >>> +++ b/drivers/mtd/nand/mxs_nand.c > >>> @@ -305,7 +305,7 @@ static void mxs_nand_cmd_ctrl(struct mtd_info > >>> *mtd, int data, unsigned int ctrl) > >>> > >>> d->cmd.data = > >>> > >>> MXS_DMA_DESC_COMMAND_DMA_READ | MXS_DMA_DESC_IRQ | > >>> MXS_DMA_DESC_CHAIN | MXS_DMA_DESC_DEC_SEM | > >>> > >>> - MXS_DMA_DESC_WAIT4END | (3 << MXS_DMA_DESC_PIO_WORDS_OFFSET) | > >>> + MXS_DMA_DESC_WAIT4END | (1 << MXS_DMA_DESC_PIO_WORDS_OFFSET) | > >>> > >>> (nand_info->cmd_queue_len << MXS_DMA_DESC_BYTES_OFFSET); > >> > >> What error or problem does this incorrect setup cause in your case? I'm > >> asking since I'm also using this driver in some mx6 system and have not > >> seen any issues. > > > > As far as I can see, it doesn't seem to cause any issue. But, if you > > read the iMX6 Reference Manual (chapter 14.2) this field should reflect > > the number of PIO_WORDS appended to the DMA command, in this case 1. > > Okay. I just wanted to check if this patch fixes a real problem that you > have experienced. Thanks for the explanation. > > Reviewed-by: Stefan Roese The patch does in fact change the behavior such that it no longer clears the ECCCTRL and COMPARE registers both on MX28 and on MX6 . Could this have some impact? Best regards, Marek Vasut