[PATCH] fpga-manager: altera-ps-spi: preserve nCONFIG state

[PATCH] fpga-manager: altera-ps-spi: preserve nCONFIG state

[Moritz Fischer]

From: Anatolij Gustschin <agust@denx.de>

If the driver module is loaded when FPGA is configured, the FPGA
is reset because nconfig is pulled low (low-active gpio inited
with GPIOD_OUT_HIGH activates the signal which means setting its
value to low). Init nconfig with GPIOD_OUT_LOW to prevent this.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Acked-by: Alan Tull <atull@kernel.org>
Signed-off-by: Moritz Fischer <mdf@kernel.org>
Cc: stable <stable@vger.kernel.org> # 4.14+
---

Hi Greg,

as discussed. Can you please take this bugfix for 4.17?
I rebased it against next.

Thanks,

Moritz

PS: Sorry for late submission
---
 drivers/fpga/altera-ps-spi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
index 14f14efdf0d5..06d212a3d49d 100644
--- a/drivers/fpga/altera-ps-spi.c
+++ b/drivers/fpga/altera-ps-spi.c
@@ -249,7 +249,7 @@ static int altera_ps_probe(struct spi_device *spi)
 
 	conf->data = of_id->data;
 	conf->spi = spi;
-	conf->config = devm_gpiod_get(&spi->dev, "nconfig", GPIOD_OUT_HIGH);
+	conf->config = devm_gpiod_get(&spi->dev, "nconfig", GPIOD_OUT_LOW);
 	if (IS_ERR(conf->config)) {
 		dev_err(&spi->dev, "Failed to get config gpio: %ld\n",
 			PTR_ERR(conf->config));
-- 
2.17.0

Re: [PATCH] fpga-manager: altera-ps-spi: preserve nCONFIG state

[Greg KH]

On Sun, Apr 15, 2018 at 11:33:08AM -0700, Moritz Fischer wrote:
> From: Anatolij Gustschin <agust@denx.de>
> 
> If the driver module is loaded when FPGA is configured, the FPGA
> is reset because nconfig is pulled low (low-active gpio inited
> with GPIOD_OUT_HIGH activates the signal which means setting its
> value to low). Init nconfig with GPIOD_OUT_LOW to prevent this.
> 
> Signed-off-by: Anatolij Gustschin <agust@denx.de>
> Acked-by: Alan Tull <atull@kernel.org>
> Signed-off-by: Moritz Fischer <mdf@kernel.org>
> ---
> 
> Hi Greg,
> 
> as discussed. Can you please take this bugfix for 4.17?
> I rebased it against next.

Is it also needed in any older kernel versions?

thanks,

greg k-h

Re: [PATCH] fpga-manager: altera-ps-spi: preserve nCONFIG state

[Anatolij Gustschin]

On Mon, 16 Apr 2018 10:10:08 +0200
Greg KH gregkh@linuxfoundation.org wrote:
...
>> as discussed. Can you please take this bugfix for 4.17?
>> I rebased it against next.  
>
>Is it also needed in any older kernel versions?

It is needed in versions starting from v4.14.

thanks,

Anatolij