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Message-ID: <CAC=U0a3jaNxRbScy27L+BFCs872F0kLAH80ieZNc7Uq6LwOyEQ@mail.gmail.com>
Date: Tue, 25 Jul 2017 17:39:57 -0400
From: Kamal Dasu <kdasu.kdev@...il.com>
To: Arnd Bergmann <arnd@...db.de>
Cc: Mark Brown <broonie@...nel.org>,
Cyrille Pitchen <cyrille.pitchen@...el.com>,
Geert Uytterhoeven <geert+renesas@...der.be>,
Hauke Mehrtens <hauke@...ke-m.de>,
linux-spi <linux-spi@...r.kernel.org>,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH] spi: document broadcom qspi driver as broken
Arnd, Cyrille,
I am working on fixing spi-bcm-qspi.c as per Cyrill's suggestion as
mentioned here : https://patchwork.kernel.org/patch/9624585/.
And remove the use of SPINOR_OP_READ* and there by remove need to
include spi-nor.h.
Thanks
Kamal
On Fri, Jul 21, 2017 at 6:00 PM, Arnd Bergmann <arnd@...db.de> wrote:
> The newly broadcom qspi driver in drivers/spi produces a build
> warning when CONFIG_MTD is disabled:
>
> include/linux/mtd/cfi.h:76:2: #warning No CONFIG_MTD_CFI_Ix selected. No NOR chip support can work. [-Werror=cpp]
>
> I had suggested a workaround earlier, but Cyrille Pitchen explained
> that actually the broadcom qspi is broken here and needs to be
> fixed, see the lenghthy reply in patchwork.
>
> As nothing has happened on that driver, this tries to at least
> avoid the build failure, by marking the driver as broken unless
> CONFIG_MTD is enabled. Also, I add a WARN_ON_ONCE runtime
> that triggers when the spi-nor framework and the driver disagree
> about the command opcode, which was one of several issues that
> Cyrille pointed out.
>
> My patch does not attempt to fix any of the actual bugs though,
> it just tries to avoid the build error while highlighting the
> problems. Ideally, someone would step up to create a tested
> fix. If that doesn't happen, please merge my version instead
> as a workaround.
>
> Fixes: fa236a7ef240 ("spi: bcm-qspi: Add Broadcom MSPI driver")
> Link: https://patchwork.kernel.org/patch/9334097/
> Link: https://patchwork.kernel.org/patch/9624585/
> Signed-off-by: Arnd Bergmann <arnd@...db.de>
> Cc: Cyrille Pitchen <cyrille.pitchen@...el.com>
> ---
> ---
> drivers/spi/Kconfig | 1 +
> drivers/spi/spi-bcm-qspi.c | 23 ++++++++++++-----------
> 2 files changed, 13 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> index 9b31351fe429..c7a80f9d6dd0 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -164,6 +164,7 @@ config SPI_BCM_QSPI
> tristate "Broadcom BSPI and MSPI controller support"
> depends on ARCH_BRCMSTB || ARCH_BCM || ARCH_BCM_IPROC || \
> BMIPS_GENERIC || COMPILE_TEST
> + depends on BROKEN || MTD
> default ARCH_BCM_IPROC
> help
> Enables support for the Broadcom SPI flash and MSPI controller.
> diff --git a/drivers/spi/spi-bcm-qspi.c b/drivers/spi/spi-bcm-qspi.c
> index b19722ba908c..a388a3873552 100644
> --- a/drivers/spi/spi-bcm-qspi.c
> +++ b/drivers/spi/spi-bcm-qspi.c
> @@ -349,12 +349,13 @@ static void bcm_qspi_bspi_set_xfer_params(struct bcm_qspi *qspi, u8 cmd_byte,
> bcm_qspi_write(qspi, BSPI, BSPI_FLEX_MODE_ENABLE, flex_mode);
> }
>
> -static int bcm_qspi_bspi_set_flex_mode(struct bcm_qspi *qspi, int width,
> - int addrlen, int hp)
> +static int bcm_qspi_bspi_set_flex_mode(struct bcm_qspi *qspi,
> + struct spi_flash_read_message *msg,
> + int width, int addrlen, int hp)
> {
> int bpc = 0, bpp = 0;
> u8 command = SPINOR_OP_READ_FAST;
> - int flex_mode = 1, rv = 0;
> + int flex_mode = 1;
> bool spans_4byte = false;
>
> dev_dbg(&qspi->pdev->dev, "set flex mode w %x addrlen %x hp %d\n",
> @@ -405,15 +406,14 @@ static int bcm_qspi_bspi_set_flex_mode(struct bcm_qspi *qspi, int width,
> }
> break;
> default:
> - rv = -EINVAL;
> - break;
> + return -EINVAL;
> }
>
> - if (rv == 0)
> - bcm_qspi_bspi_set_xfer_params(qspi, command, bpp, bpc,
> - flex_mode);
> + WARN_ON_ONCE(command != msg->read_opcode);
>
> - return rv;
> + bcm_qspi_bspi_set_xfer_params(qspi, command, bpp, bpc,
> + flex_mode);
> + return 0;
> }
>
> static int bcm_qspi_bspi_set_override(struct bcm_qspi *qspi, int width,
> @@ -461,6 +461,7 @@ static int bcm_qspi_bspi_set_override(struct bcm_qspi *qspi, int width,
> }
>
> static int bcm_qspi_bspi_set_mode(struct bcm_qspi *qspi,
> + struct spi_flash_read_message *msg,
> int width, int addrlen, int hp)
> {
> int error = 0;
> @@ -491,7 +492,7 @@ static int bcm_qspi_bspi_set_mode(struct bcm_qspi *qspi,
> }
>
> if (qspi->xfer_mode.flex_mode)
> - error = bcm_qspi_bspi_set_flex_mode(qspi, width, addrlen, hp);
> + error = bcm_qspi_bspi_set_flex_mode(qspi, msg, width, addrlen, hp);
>
> if (error) {
> dev_warn(&qspi->pdev->dev,
> @@ -1012,7 +1013,7 @@ static int bcm_qspi_flash_read(struct spi_device *spi,
>
> io_width = msg->data_nbits ? msg->data_nbits : SPI_NBITS_SINGLE;
> addrlen = msg->addr_width;
> - ret = bcm_qspi_bspi_set_mode(qspi, io_width, addrlen, -1);
> + ret = bcm_qspi_bspi_set_mode(qspi, msg, io_width, addrlen, -1);
>
> if (!ret)
> ret = bcm_qspi_bspi_flash_read(spi, msg);
> --
> 2.9.0
>
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