From mboxrd@z Thu Jan 1 00:00:00 1970 From: leiwen@marvell.com (Lei Wen) Date: Thu, 14 Jul 2011 20:44:30 -0700 Subject: [PATCH V8 1/4] MTD: pxa3xx_nand: enhance suspend and resume routine In-Reply-To: <1310481336-13230-1-git-send-email-leiwen@marvell.com> References: <1310481336-13230-1-git-send-email-leiwen@marvell.com> Message-ID: <1310701473-31632-2-git-send-email-leiwen@marvell.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org This patch add protection on the suspend&resume path to prevent some unexpected behavior, like interrupt occur at the very second of resume back and it don't follow normal command path, which lead to bug. Signed-off-by: Lei Wen --- drivers/mtd/nand/pxa3xx_nand.c | 15 ++++++++++++++- 1 files changed, 14 insertions(+), 1 deletions(-) diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c index b7db1b2..61e1ff5 100644 --- a/drivers/mtd/nand/pxa3xx_nand.c +++ b/drivers/mtd/nand/pxa3xx_nand.c @@ -1158,23 +1158,36 @@ static int pxa3xx_nand_probe(struct platform_device *pdev) static int pxa3xx_nand_suspend(struct platform_device *pdev, pm_message_t state) { struct pxa3xx_nand_info *info = platform_get_drvdata(pdev); + struct mtd_info *mtd = info->mtd; if (info->state) { dev_err(&pdev->dev, "driver busy, state = %d\n", info->state); return -EAGAIN; } + mtd->suspend(mtd); return 0; } static int pxa3xx_nand_resume(struct platform_device *pdev) { struct pxa3xx_nand_info *info = platform_get_drvdata(pdev); + struct mtd_info *mtd = info->mtd; + + /* We don't want to handle interrupt without calling mtd routine */ + disable_int(info, NDCR_INT_MASK); nand_writel(info, NDTR0CS0, info->ndtr0cs0); nand_writel(info, NDTR1CS0, info->ndtr1cs0); - clk_enable(info->clk); + /* + * As the spec says, the NDSR would be updated to 0x1800 when + * doing the nand_clk disable/enable. + * To prevent it damaging state machine of the driver, clear + * all status before resume + */ + nand_writel(info, NDSR, NDSR_MASK); + mtd->resume(mtd); return 0; } #else -- 1.7.0.4