From: Eddie James <eajames@linux.vnet.ibm.com>
To: Joel Stanley <joel@jms.id.au>,
openbmc@lists.ozlabs.org, Eddie James <eajames@linux.ibm.com>,
Andrew Jeffery <andrew@aj.id.au>
Subject: Re: [PATCH linux dev-5.4 1/2] fsi: aspeed: Run the bus at maximum speed
Date: Tue, 14 Apr 2020 17:27:08 -0500 [thread overview]
Message-ID: <7d1d8fe8-f033-8853-1adc-08f1de769007@linux.vnet.ibm.com> (raw)
In-Reply-To: <20200414105140.1089095-2-joel@jms.id.au>
On 4/14/20 5:51 AM, Joel Stanley wrote:
> Testing of Tacoma has shown that the ASPEED master can be run at maximum
> speed.
>
> The exception is when wired externally with a cable, in which case we
> use a divisor of two to ensure reliable operation.
Reviewed-by: Eddie James <eajames@linux.ibm.com>
>
> Signed-off-by: Joel Stanley <joel@jms.id.au>
> ---
> drivers/fsi/fsi-master-aspeed.c | 17 ++++++++++++++---
> 1 file changed, 14 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/fsi/fsi-master-aspeed.c b/drivers/fsi/fsi-master-aspeed.c
> index fe2da6f90590..80bc9132e4f8 100644
> --- a/drivers/fsi/fsi-master-aspeed.c
> +++ b/drivers/fsi/fsi-master-aspeed.c
> @@ -83,7 +83,11 @@ static const u32 fsi_base = 0xa0000000;
>
> #define FSI_LINK_ENABLE_SETUP_TIME 10 /* in mS */
>
> -#define DEFAULT_DIVISOR 14
> +/* Run the bus at maximum speed by default */
> +#define FSI_DIVISOR_DEFAULT 1
> +#define FSI_DIVISOR_CABLED 2
> +static u16 aspeed_fsi_divisor = FSI_DIVISOR_DEFAULT;
> +
> #define OPB_POLL_TIMEOUT 10000
>
> static int __opb_write(struct fsi_master_aspeed *aspeed, u32 addr,
> @@ -389,9 +393,11 @@ static int aspeed_master_init(struct fsi_master_aspeed *aspeed)
> opb_writel(aspeed, ctrl_base + FSI_MECTRL, reg);
>
> reg = cpu_to_be32(FSI_MMODE_ECRC | FSI_MMODE_EPC | FSI_MMODE_RELA
> - | fsi_mmode_crs0(DEFAULT_DIVISOR)
> - | fsi_mmode_crs1(DEFAULT_DIVISOR)
> + | fsi_mmode_crs0(aspeed_fsi_divisor)
> + | fsi_mmode_crs1(aspeed_fsi_divisor)
> | FSI_MMODE_P8_TO_LSB);
> + dev_info(aspeed->dev, "mmode set to %08x (divisor %d)\n",
> + be32_to_cpu(reg), aspeed_fsi_divisor);
> opb_writel(aspeed, ctrl_base + FSI_MMODE, reg);
>
> reg = cpu_to_be32(0xffff0000);
> @@ -450,6 +456,11 @@ static int tacoma_cabled_fsi_fixup(struct device *dev)
>
> /* If the routing GPIO is high we should set the mux to low. */
> if (gpio) {
> + /*
> + * Cable signal integrity means we should run the bus
> + * slightly slower
> + */
> + aspeed_fsi_divisor = FSI_DIVISOR_CABLED;
> gpiod_direction_output(mux_gpio, 0);
> dev_info(dev, "FSI configured for external cable\n");
> } else {
next prev parent reply other threads:[~2020-04-14 22:27 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-14 10:51 [PATCH linux dev-5.4 0/2] fsi: aspeed: Divisor settings Joel Stanley
2020-04-14 10:51 ` [PATCH linux dev-5.4 1/2] fsi: aspeed: Run the bus at maximum speed Joel Stanley
2020-04-14 22:27 ` Eddie James [this message]
2020-04-14 10:51 ` [PATCH linux dev-5.4 2/2] fsi: aspeed: Add module param for bus divisor Joel Stanley
2020-04-14 22:27 ` Eddie James
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=7d1d8fe8-f033-8853-1adc-08f1de769007@linux.vnet.ibm.com \
--to=eajames@linux.vnet.ibm.com \
--cc=andrew@aj.id.au \
--cc=eajames@linux.ibm.com \
--cc=joel@jms.id.au \
--cc=openbmc@lists.ozlabs.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.