2018-04-15 18:36:46

by Moritz Fischer

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

From: Anatolij Gustschin <[email protected]>

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 <[email protected]>
Acked-by: Alan Tull <[email protected]>
Signed-off-by: Moritz Fischer <[email protected]>
---

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

2018-04-16 08:33:12

by Greg Kroah-Hartman

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

On Sun, Apr 15, 2018 at 11:33:08AM -0700, Moritz Fischer wrote:
> From: Anatolij Gustschin <[email protected]>
>
> 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 <[email protected]>
> Acked-by: Alan Tull <[email protected]>
> Signed-off-by: Moritz Fischer <[email protected]>
> ---
>
> 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

2018-04-16 09:38:32

by Anatolij Gustschin

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

On Mon, 16 Apr 2018 10:10:08 +0200
Greg KH [email protected] 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