All of lore.kernel.org
 help / color / mirror / Atom feed
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jeremy Kerr <jk@ozlabs.org>, Joel Stanley <joel@jms.id.au>,
	Christopher Bostic <cbostic@linux.vnet.ibm.com>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>
Subject: [PATCH 06/15] fsi/fsi-master-gpio: Reduce turnaround clocks
Date: Tue, 29 May 2018 11:30:35 +1000	[thread overview]
Message-ID: <20180529013044.23815-7-benh@kernel.crashing.org> (raw)
In-Reply-To: <20180529013044.23815-1-benh@kernel.crashing.org>

FSI_GPIO_PRIME_SLAVE_CLOCKS is the number of clocks if the
"idle" phase between the end of a response and the beginning
of the next one. It corresponds to tSendDelay in the FSI
specification.

The default value in the slave is 16 clocks. 100 is way overkill
and significantly reduces the driver performance.

This changes it to 20 (which gives the HW a bit of margin still
just in case).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
---
 drivers/fsi/fsi-master-gpio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/fsi/fsi-master-gpio.c b/drivers/fsi/fsi-master-gpio.c
index c82bbd35276e..029b0a5b6d89 100644
--- a/drivers/fsi/fsi-master-gpio.c
+++ b/drivers/fsi/fsi-master-gpio.c
@@ -49,7 +49,7 @@
 #define	FSI_GPIO_CRC_SIZE	4
 #define	FSI_GPIO_MSG_ID_SIZE		2
 #define	FSI_GPIO_MSG_RESPID_SIZE	2
-#define	FSI_GPIO_PRIME_SLAVE_CLOCKS	100
+#define	FSI_GPIO_PRIME_SLAVE_CLOCKS	20
 
 struct fsi_master_gpio {
 	struct fsi_master	master;
-- 
2.17.0

  parent reply	other threads:[~2018-05-29  1:32 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-29  1:30 [PATCH 00/15] fsi: Overall improvements and new SBE fifo driver Benjamin Herrenschmidt
2018-05-29  1:30 ` [PATCH 01/15] fsi: gpio: Trace busy count Benjamin Herrenschmidt
2018-05-29  1:30 ` [PATCH 02/15] fsi: gpio: Remove unused 'id' variable Benjamin Herrenschmidt
2018-05-29  1:30 ` [PATCH 03/15] fsi: gpio: Use a mutex to protect transfers Benjamin Herrenschmidt
2018-05-29  1:30 ` [PATCH 04/15] fsi/fsi-master-gpio: Sample input data on different clock phase Benjamin Herrenschmidt
2018-05-29  1:30 ` [PATCH 05/15] fsi/fsi-master-gpio: Add "no-gpio-delays" option Benjamin Herrenschmidt
2018-05-29  1:42   ` Benjamin Herrenschmidt
2018-05-29  1:43   ` [PATCH] dt-bindings: fsi-master-gpio: Document "no-gpio-delays" property Benjamin Herrenschmidt
2018-05-31 17:13     ` Rob Herring
2018-05-29  1:30 ` Benjamin Herrenschmidt [this message]
2018-05-29  1:30 ` [PATCH 07/15] fsi/fsi-master-gpio: Reduce dpoll clocks Benjamin Herrenschmidt
2018-05-29  1:30 ` [PATCH 08/15] fsi/fsi-master-gpio: Delay sampling of FSI data input Benjamin Herrenschmidt
2018-05-29  1:30 ` [PATCH 09/15] fsi/gpio: Include command build in locked section Benjamin Herrenschmidt
2018-05-29  1:30 ` [PATCH 10/15] fsi/gpio: Use relative-addressing commands Benjamin Herrenschmidt
2018-05-29  1:30 ` [PATCH 11/15] fsi/fsi-master-gpio: Implement CRC error recovery Benjamin Herrenschmidt
2018-05-29  1:30 ` [PATCH 12/15] fsi/fsi-master-gpio: More error handling cleanup Benjamin Herrenschmidt
2018-05-29  1:30 ` [PATCH 13/15] fsi/master-gpio: Replace bit_bit lock with IRQ disable/enable Benjamin Herrenschmidt
2018-05-29  1:30 ` [PATCH 14/15] fsi: scom: Remove PIB reset during probe Benjamin Herrenschmidt
2018-05-29  1:30 ` [PATCH 15/15] fsi/sbefifo: Add driver for the SBE FIFO Benjamin Herrenschmidt
2018-05-29 12:30 ` [PATCH 00/15] fsi: Overall improvements and new SBE fifo driver Joel Stanley
2018-06-10  6:46   ` Benjamin Herrenschmidt
2018-06-10  6:57     ` Greg Kroah-Hartman

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=20180529013044.23815-7-benh@kernel.crashing.org \
    --to=benh@kernel.crashing.org \
    --cc=cbostic@linux.vnet.ibm.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=jk@ozlabs.org \
    --cc=joel@jms.id.au \
    --cc=linux-kernel@vger.kernel.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.