From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from down.free-electrons.com ([37.187.137.238] helo=mail.free-electrons.com) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1bEfYY-00049h-MM for linux-mtd@lists.infradead.org; Sun, 19 Jun 2016 16:26:43 +0000 Date: Sun, 19 Jun 2016 18:26:20 +0200 From: Boris Brezillon To: Hauke Mehrtens Cc: richard@nod.at, dwmw2@infradead.org, computersforpeace@gmail.com, linux-mtd@lists.infradead.org, john@phrozen.org Subject: Re: [PATCH v3 5/8] MTD: xway: fix nand locking Message-ID: <20160619182620.0eea56b3@bbrezillon> In-Reply-To: <1466352497-6806-6-git-send-email-hauke@hauke-m.de> References: <1466352497-6806-1-git-send-email-hauke@hauke-m.de> <1466352497-6806-6-git-send-email-hauke@hauke-m.de> 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 Sun, 19 Jun 2016 18:08:14 +0200 Hauke Mehrtens wrote: > From: John Crispin > > The external Bus Unit (EBU) can control different flash devices, but > these NAND flash commands have to be atomic and should not be > interrupted in between. Lock the EBU from the beginning of the command > till the end by moving the lock to the chip select. > > Signed-off-by: John Crispin > Signed-off-by: Hauke Mehrtens > --- > drivers/mtd/nand/xway_nand.c | 20 ++++++++------------ > 1 file changed, 8 insertions(+), 12 deletions(-) > > diff --git a/drivers/mtd/nand/xway_nand.c b/drivers/mtd/nand/xway_nand.c > index 8a0019a..618cf34 100644 > --- a/drivers/mtd/nand/xway_nand.c > +++ b/drivers/mtd/nand/xway_nand.c > @@ -65,17 +65,22 @@ > > struct xway_nand_data { > struct nand_chip chip; > + unsigned long csflags; > }; > > -static void xway_select_chip(struct mtd_info *mtd, int chip) > +static void xway_select_chip(struct mtd_info *mtd, int select) > { > + struct nand_chip *chip = mtd_to_nand(mtd); > + struct xway_nand_data *data = nand_get_controller_data(chip); > > - switch (chip) { > + switch (select) { > case -1: > ltq_ebu_w32_mask(NAND_CON_CE, 0, EBU_NAND_CON); > ltq_ebu_w32_mask(NAND_CON_NANDM, 0, EBU_NAND_CON); > + spin_unlock_irqrestore(&ebu_lock, data->csflags); > break; > case 0: > + spin_lock_irqsave(&ebu_lock, data->csflags); > ltq_ebu_w32_mask(0, NAND_CON_NANDM, EBU_NAND_CON); > ltq_ebu_w32_mask(0, NAND_CON_CE, EBU_NAND_CON); > break; > @@ -88,12 +93,10 @@ static void xway_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl) > { > struct nand_chip *this = mtd_to_nand(mtd); > unsigned long nandaddr = (unsigned long) this->IO_ADDR_W; > - unsigned long flags; > > if (cmd == NAND_CMD_NONE) > return; > > - spin_lock_irqsave(&ebu_lock, flags); > if (ctrl & NAND_CLE) > writeb(cmd, (void __iomem *) (nandaddr | NAND_WRITE_CMD)); > else if (ctrl & NAND_ALE) > @@ -101,7 +104,6 @@ static void xway_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl) > > while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0) > ; > - spin_unlock_irqrestore(&ebu_lock, flags); > } > > static int xway_dev_ready(struct mtd_info *mtd) > @@ -113,14 +115,8 @@ static unsigned char xway_read_byte(struct mtd_info *mtd) > { > struct nand_chip *this = mtd_to_nand(mtd); > unsigned long nandaddr = (unsigned long) this->IO_ADDR_R; > - unsigned long flags; > - int ret; > > - spin_lock_irqsave(&ebu_lock, flags); > - ret = ltq_r8((void __iomem *)(nandaddr + NAND_READ_DATA)); > - spin_unlock_irqrestore(&ebu_lock, flags); > - > - return ret; > + return ltq_r8((void __iomem *)(nandaddr + NAND_READ_DATA)); Drop the cast and use this->IO_ADDR_R here. > } > > /*