From: Romain Izard <romain.izard.pro@gmail.com> To: Nicolas Ferre <nicolas.ferre@microchip.com>, Boris Brezillon <boris.brezillon@free-electrons.com>, Michael Turquette <mturquette@baylibre.com>, Stephen Boyd <sboyd@codeaurora.org>, Ludovic Desroches <ludovic.desroches@microchip.com>, Jonathan Cameron <jic23@kernel.org>, Wenyou Yang <wenyou.yang@atmel.com>, Josh Wu <rainyfeeling@outlook.com>, David Woodhouse <dwmw2@infradead.org>, Brian Norris <computersforpeace@gmail.com>, Marek Vasut <marek.vasut@gmail.com>, Cyrille Pitchen <cyrille.pitchen@wedev4u.fr>, Thierry Reding <thierry.reding@gmail.com>, Richard Genoud <richard.genoud@gmail.com>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Alan Stern <stern@rowland.harvard.edu> Cc: linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, linux-mtd@lists.infradead.org, linux-pwm@vger.kernel.org, linux-serial@vger.kernel.org, linux-usb@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Romain Izard <romain.izard.pro@gmail.com> Subject: [PATCH v1 04/10] mtd: nand: atmel: Avoid ECC errors when leaving backup mode Date: Fri, 8 Sep 2017 17:35:58 +0200 [thread overview] Message-ID: <20170908153604.28383-5-romain.izard.pro@gmail.com> (raw) In-Reply-To: <20170908153604.28383-1-romain.izard.pro@gmail.com> During backup mode, the contents of all registers will be cleared as the SoC will be completely powered down. For a product that boots on NAND Flash memory, the bootloader will obviously use the related controller to read the Flash and correct any detected error in the memory, before handling back control to the kernel's resuming entry point. In normal devices, it is up to the driver's suspend/resume code to restore the registers in a valid state. But the PMECC is not a regular device in the driver model when used with the legacy device tree binding for the Atmel NAND controller, and suspend/resume code is not called. As in my case the bootloader leaves the PMECC controller in a programmed state, and the controller is only reset at boot or after a NAND access, the first NAND Flash access with the Atmel controller will report uncorrectable ECC errors. To avoid this, systematically reset the PMECC controller before using it. Signed-off-by: Romain Izard <romain.izard.pro@gmail.com> --- drivers/mtd/nand/atmel/pmecc.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) diff --git a/drivers/mtd/nand/atmel/pmecc.c b/drivers/mtd/nand/atmel/pmecc.c index 8c210a5776bc..8d1208f38025 100644 --- a/drivers/mtd/nand/atmel/pmecc.c +++ b/drivers/mtd/nand/atmel/pmecc.c @@ -777,6 +777,9 @@ int atmel_pmecc_enable(struct atmel_pmecc_user *user, int op) mutex_lock(&user->pmecc->lock); + writel(PMECC_CTRL_RST, pmecc->regs.base + ATMEL_PMECC_CTRL); + writel(PMECC_CTRL_DISABLE, pmecc->regs.base + ATMEL_PMECC_CTRL); + cfg = user->cache.cfg; if (op == NAND_ECC_WRITE) cfg |= PMECC_CFG_WRITE_OP; @@ -797,10 +800,6 @@ EXPORT_SYMBOL_GPL(atmel_pmecc_enable); void atmel_pmecc_disable(struct atmel_pmecc_user *user) { - struct atmel_pmecc *pmecc = user->pmecc; - - writel(PMECC_CTRL_RST, pmecc->regs.base + ATMEL_PMECC_CTRL); - writel(PMECC_CTRL_DISABLE, pmecc->regs.base + ATMEL_PMECC_CTRL); mutex_unlock(&user->pmecc->lock); } EXPORT_SYMBOL_GPL(atmel_pmecc_disable); @@ -856,10 +855,6 @@ static struct atmel_pmecc *atmel_pmecc_create(struct platform_device *pdev, /* Disable all interrupts before registering the PMECC handler. */ writel(0xffffffff, pmecc->regs.base + ATMEL_PMECC_IDR); - /* Reset the ECC engine */ - writel(PMECC_CTRL_RST, pmecc->regs.base + ATMEL_PMECC_CTRL); - writel(PMECC_CTRL_DISABLE, pmecc->regs.base + ATMEL_PMECC_CTRL); - return pmecc; } -- 2.11.0
WARNING: multiple messages have this Message-ID (diff)
From: romain.izard.pro@gmail.com (Romain Izard) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v1 04/10] mtd: nand: atmel: Avoid ECC errors when leaving backup mode Date: Fri, 8 Sep 2017 17:35:58 +0200 [thread overview] Message-ID: <20170908153604.28383-5-romain.izard.pro@gmail.com> (raw) In-Reply-To: <20170908153604.28383-1-romain.izard.pro@gmail.com> During backup mode, the contents of all registers will be cleared as the SoC will be completely powered down. For a product that boots on NAND Flash memory, the bootloader will obviously use the related controller to read the Flash and correct any detected error in the memory, before handling back control to the kernel's resuming entry point. In normal devices, it is up to the driver's suspend/resume code to restore the registers in a valid state. But the PMECC is not a regular device in the driver model when used with the legacy device tree binding for the Atmel NAND controller, and suspend/resume code is not called. As in my case the bootloader leaves the PMECC controller in a programmed state, and the controller is only reset at boot or after a NAND access, the first NAND Flash access with the Atmel controller will report uncorrectable ECC errors. To avoid this, systematically reset the PMECC controller before using it. Signed-off-by: Romain Izard <romain.izard.pro@gmail.com> --- drivers/mtd/nand/atmel/pmecc.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) diff --git a/drivers/mtd/nand/atmel/pmecc.c b/drivers/mtd/nand/atmel/pmecc.c index 8c210a5776bc..8d1208f38025 100644 --- a/drivers/mtd/nand/atmel/pmecc.c +++ b/drivers/mtd/nand/atmel/pmecc.c @@ -777,6 +777,9 @@ int atmel_pmecc_enable(struct atmel_pmecc_user *user, int op) mutex_lock(&user->pmecc->lock); + writel(PMECC_CTRL_RST, pmecc->regs.base + ATMEL_PMECC_CTRL); + writel(PMECC_CTRL_DISABLE, pmecc->regs.base + ATMEL_PMECC_CTRL); + cfg = user->cache.cfg; if (op == NAND_ECC_WRITE) cfg |= PMECC_CFG_WRITE_OP; @@ -797,10 +800,6 @@ EXPORT_SYMBOL_GPL(atmel_pmecc_enable); void atmel_pmecc_disable(struct atmel_pmecc_user *user) { - struct atmel_pmecc *pmecc = user->pmecc; - - writel(PMECC_CTRL_RST, pmecc->regs.base + ATMEL_PMECC_CTRL); - writel(PMECC_CTRL_DISABLE, pmecc->regs.base + ATMEL_PMECC_CTRL); mutex_unlock(&user->pmecc->lock); } EXPORT_SYMBOL_GPL(atmel_pmecc_disable); @@ -856,10 +855,6 @@ static struct atmel_pmecc *atmel_pmecc_create(struct platform_device *pdev, /* Disable all interrupts before registering the PMECC handler. */ writel(0xffffffff, pmecc->regs.base + ATMEL_PMECC_IDR); - /* Reset the ECC engine */ - writel(PMECC_CTRL_RST, pmecc->regs.base + ATMEL_PMECC_CTRL); - writel(PMECC_CTRL_DISABLE, pmecc->regs.base + ATMEL_PMECC_CTRL); - return pmecc; } -- 2.11.0
next prev parent reply other threads:[~2017-09-08 15:36 UTC|newest] Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-09-08 15:35 [PATCH v1 00/10] Various patches for SAMA5D2 backup mode Romain Izard 2017-09-08 15:35 ` Romain Izard 2017-09-08 15:35 ` [PATCH v1 01/10] clk: at91: pmc: Wait for clocks when resuming Romain Izard 2017-09-08 15:35 ` Romain Izard 2017-09-13 12:15 ` Nicolas Ferre 2017-09-13 12:15 ` Nicolas Ferre 2017-09-13 12:15 ` Nicolas Ferre 2017-09-14 16:15 ` Romain Izard 2017-09-14 16:15 ` Romain Izard 2017-09-14 16:15 ` Romain Izard 2017-09-22 12:12 ` Nicolas Ferre 2017-09-22 12:12 ` Nicolas Ferre 2017-09-22 12:12 ` Nicolas Ferre 2017-09-08 15:35 ` [PATCH v1 02/10] clk: at91: pmc: Save SCSR during suspend Romain Izard 2017-09-08 15:35 ` Romain Izard 2017-09-08 15:35 ` Romain Izard 2017-09-13 12:10 ` Nicolas Ferre 2017-09-13 12:10 ` Nicolas Ferre 2017-09-13 12:10 ` Nicolas Ferre 2017-09-08 15:35 ` [PATCH v1 03/10] clk: at91: pmc: Support backup for programmable clocks Romain Izard 2017-09-08 15:35 ` Romain Izard 2017-09-13 12:29 ` Nicolas Ferre 2017-09-13 12:29 ` Nicolas Ferre 2017-09-13 12:29 ` Nicolas Ferre 2017-09-13 17:03 ` Alexandre Belloni 2017-09-13 17:03 ` Alexandre Belloni 2017-09-13 17:03 ` Alexandre Belloni 2017-09-14 7:41 ` romain izard 2017-09-14 7:41 ` romain izard 2017-09-14 7:41 ` romain izard 2017-09-14 9:38 ` Nicolas Ferre 2017-09-14 9:38 ` Nicolas Ferre 2017-09-14 9:38 ` Nicolas Ferre 2017-09-08 15:35 ` Romain Izard [this message] 2017-09-08 15:35 ` [PATCH v1 04/10] mtd: nand: atmel: Avoid ECC errors when leaving backup mode Romain Izard 2017-09-08 15:35 ` [PATCH v1 05/10] mtd: nand: atmel: Report PMECC failures as errors Romain Izard 2017-09-08 15:35 ` Romain Izard 2017-09-08 15:36 ` [PATCH v1 06/10] ehci-atmel: Power down during suspend is normal Romain Izard 2017-09-08 15:36 ` Romain Izard 2017-09-08 15:36 ` [PATCH v1 07/10] iio:adc:at91-sama5d2: Support backup mode Romain Izard 2017-09-08 15:36 ` Romain Izard 2017-09-08 16:03 ` Nicolas Ferre 2017-09-08 16:03 ` Nicolas Ferre 2017-09-08 16:03 ` Nicolas Ferre 2017-09-08 16:21 ` Romain Izard 2017-09-08 16:21 ` Romain Izard 2017-09-08 16:21 ` Romain Izard 2017-09-08 15:36 ` [PATCH v1 08/10] pwm: atmel-tcb: " Romain Izard 2017-09-08 15:36 ` Romain Izard 2017-09-08 15:36 ` Romain Izard 2017-09-08 15:36 ` [PATCH v1 09/10] atmel_flexcom: " Romain Izard 2017-09-08 15:36 ` Romain Izard 2017-09-08 15:36 ` [PATCH v1 10/10] tty/serial: atmel: Prevent a warning on suspend Romain Izard 2017-09-08 15:36 ` Romain Izard 2017-09-08 15:36 ` Romain Izard 2017-09-11 9:52 ` Romain Izard 2017-09-11 9:52 ` Romain Izard 2017-09-11 9:52 ` Romain Izard
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