From mboxrd@z Thu Jan 1 00:00:00 1970 From: leiwen@marvell.com (Lei Wen) Date: Tue, 12 Jul 2011 03:28:55 -0700 Subject: [PATCH V6 4/4] MTD: pxa3xx_nand: enhance suspend and resume routine In-Reply-To: <1310096084-14646-1-git-send-email-leiwen@marvell.com> References: <1310096084-14646-1-git-send-email-leiwen@marvell.com> Message-ID: <1310466535-15287-5-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 | 28 ++++++++++++++++++++++++++++ 1 files changed, 28 insertions(+), 0 deletions(-) diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c index 3756d54..35149fe 100644 --- a/drivers/mtd/nand/pxa3xx_nand.c +++ b/drivers/mtd/nand/pxa3xx_nand.c @@ -1246,18 +1246,34 @@ 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 pxa3xx_nand_platform_data *pdata; + struct mtd_info *mtd; + int cs; + pdata = pdev->dev.platform_data; if (info->state) { dev_err(&pdev->dev, "driver busy, state = %d\n", info->state); return -EAGAIN; } + for (cs = 0; cs < pdata->num_cs; cs ++) { + mtd = info->host[cs]->mtd; + mtd->suspend(mtd); + } + + clk_disable(info->clk); return 0; } static int pxa3xx_nand_resume(struct platform_device *pdev) { struct pxa3xx_nand_info *info = platform_get_drvdata(pdev); + struct pxa3xx_nand_platform_data *pdata; + int cs; + + pdata = pdev->dev.platform_data; + /* We don't want to handle interrupt without calling mtd routine */ + disable_int(info, NDCR_INT_MASK); /* * Directly set the chip select to a invalid value, @@ -1267,6 +1283,18 @@ static int pxa3xx_nand_resume(struct platform_device *pdev) info->cs = 0xff; clk_enable(info->clk); + /* + * As the spec, the NDSR would be updated to 0x1800 when + * do the nand_clk disable/enable. + * To prevent it damage state machine of the driver, clear + * all status before resume + */ + nand_writel(nand, NDSR, NDSR_MASK); + for (cs = 0; cs < pdata->num_cs; cs ++) { + mtd = info->host[cs]->mtd; + mtd->resume(mtd); + } + return 0; } #else -- 1.7.0.4