From: Jan Glauber <jglauber@cavium.com>
To: Wolfram Sang <wsa@the-dreams.de>
Cc: linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org,
David Daney <ddaney@caviumnetworks.com>,
David Daney <david.daney@cavium.com>,
Jan Glauber <jglauber@cavium.com>
Subject: [PATCH v6 13/19] i2c: octeon: Add workaround for broken irqs on CN3860
Date: Mon, 11 Apr 2016 17:28:44 +0200 [thread overview]
Message-ID: <3e9c18a66b449837ace80e1c86f0a6fd6a638a9d.1460387640.git.jglauber@cavium.com> (raw)
In-Reply-To: <cover.1460387640.git.jglauber@cavium.com>
In-Reply-To: <cover.1460387640.git.jglauber@cavium.com>
From: David Daney <david.daney@cavium.com>
CN3860 does not interrupt the CPU when the i2c status changes. If
we get a timeout, and see the status has in fact changed, we know we
have this problem, and drop back to polling.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
---
drivers/i2c/busses/i2c-octeon.c | 55 +++++++++++++++++++++++++++++++++++++++--
1 file changed, 53 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index bad49cf..bfaee37 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -119,6 +119,8 @@ struct octeon_i2c {
void __iomem *twsi_base;
struct device *dev;
bool hlc_enabled;
+ bool broken_irq_mode;
+ bool broken_irq_check;
void (*int_en)(struct octeon_i2c *);
void (*int_dis)(struct octeon_i2c *);
void (*hlc_int_en)(struct octeon_i2c *);
@@ -378,10 +380,33 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)
long time_left;
int first = 1;
+ if (i2c->broken_irq_mode) {
+ /*
+ * Some chip revisions seem to not assert the irq in
+ * the interrupt controller. So we must poll for the
+ * IFLG change.
+ */
+ u64 end = get_jiffies_64() + i2c->adap.timeout;
+
+ while (!octeon_i2c_test_iflg(i2c) &&
+ time_before64(get_jiffies_64(), end))
+ udelay(50);
+
+ return octeon_i2c_test_iflg(i2c) ? 0 : -ETIMEDOUT;
+ }
+
i2c->int_en(i2c);
time_left = wait_event_timeout(i2c->queue, poll_iflg(i2c, &first),
i2c->adap.timeout);
i2c->int_dis(i2c);
+
+ if (time_left <= 0 && i2c->broken_irq_check &&
+ octeon_i2c_test_iflg(i2c)) {
+ dev_err(i2c->dev,
+ "broken irq connection detected, switching to polling mode.\n");
+ i2c->broken_irq_mode = true;
+ return 0;
+ }
if (!time_left) {
dev_dbg(i2c->dev, "%s: timeout\n", __func__);
return -ETIMEDOUT;
@@ -477,17 +502,40 @@ static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
{
int time_left;
+ if (i2c->broken_irq_mode) {
+ /*
+ * Some cn38xx boards did not assert the irq in
+ * the interrupt controller. So we must poll for the
+ * IFLG change.
+ */
+ u64 end = get_jiffies_64() + i2c->adap.timeout;
+
+ while (!octeon_i2c_hlc_test_ready(i2c) &&
+ time_before64(get_jiffies_64(), end))
+ udelay(50);
+
+ return octeon_i2c_hlc_test_ready(i2c) ? 0 : -ETIMEDOUT;
+ }
+
i2c->hlc_int_en(i2c);
time_left = wait_event_interruptible_timeout(i2c->queue,
octeon_i2c_hlc_test_ready(i2c),
i2c->adap.timeout);
i2c->hlc_int_dis(i2c);
- if (!time_left) {
+ if (!time_left)
octeon_i2c_hlc_int_clear(i2c);
+
+ if (time_left <= 0 && i2c->broken_irq_check &&
+ octeon_i2c_hlc_test_ready(i2c)) {
+ dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n");
+ i2c->broken_irq_mode = true;
+ return 0;
+ }
+
+ if (!time_left) {
dev_dbg(i2c->dev, "%s: timeout\n", __func__);
return -ETIMEDOUT;
}
-
if (time_left < 0) {
dev_dbg(i2c->dev, "%s: wait interrupted\n", __func__);
return time_left;
@@ -1143,6 +1191,9 @@ static int octeon_i2c_probe(struct platform_device *pdev)
goto out;
}
+ if (OCTEON_IS_MODEL(OCTEON_CN38XX))
+ i2c->broken_irq_check = true;
+
result = octeon_i2c_init_lowlevel(i2c);
if (result) {
dev_err(i2c->dev, "init low level failed\n");
--
1.9.1
next prev parent reply other threads:[~2016-04-11 15:29 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-11 15:28 [PATCH v6 00/19] i2c-octeon and i2c-thunderx drivers Jan Glauber
2016-04-11 15:28 ` [PATCH v6 01/19] i2c: octeon: Increase retry default and use fixed timeout value Jan Glauber
2016-04-13 8:39 ` Wolfram Sang
2016-04-11 15:28 ` [PATCH v6 02/19] i2c: octeon: Move set-clock and init-lowlevel upward Jan Glauber
2016-04-13 8:39 ` Wolfram Sang
2016-04-11 15:28 ` [PATCH v6 03/19] i2c: octeon: Rename [read|write]_sw to reg_[read|write] Jan Glauber
2016-04-13 8:44 ` Wolfram Sang
2016-04-14 7:58 ` Jan Glauber
2016-04-14 8:58 ` Wolfram Sang
2016-04-11 15:28 ` [PATCH v6 04/19] i2c: octeon: Introduce helper functions for register access Jan Glauber
2016-04-13 8:45 ` Wolfram Sang
2016-04-14 8:05 ` Jan Glauber
2016-04-14 8:58 ` Wolfram Sang
2016-04-11 15:28 ` [PATCH v6 05/19] i2c: octeon: Remove superfluous check in octeon_i2c_test_iflg Jan Glauber
2016-04-14 8:59 ` Wolfram Sang
2016-04-11 15:28 ` [PATCH v6 06/19] i2c: octeon: Improve error status checking Jan Glauber
2016-04-13 8:55 ` Wolfram Sang
2016-04-14 8:10 ` Jan Glauber
2016-04-14 9:01 ` Wolfram Sang
2016-04-11 15:28 ` [PATCH v6 07/19] i2c: octeon: Use i2c recovery framework Jan Glauber
2016-04-20 21:31 ` Wolfram Sang
2016-04-21 13:08 ` Jan Glauber
2016-04-21 13:54 ` Wolfram Sang
2016-04-21 17:51 ` Jan Glauber
2016-04-21 21:33 ` Wolfram Sang
2016-04-11 15:28 ` [PATCH v6 08/19] i2c: octeon: Enable High-Level Controller Jan Glauber
2016-04-20 21:43 ` Wolfram Sang
2016-04-20 21:55 ` David Daney
2016-04-21 13:40 ` Jan Glauber
2016-04-21 13:55 ` Wolfram Sang
2016-04-21 14:10 ` Jan Glauber
2016-04-11 15:28 ` [PATCH v6 09/19] dt-bindings: i2c: Add Octeon cn78xx TWSI Jan Glauber
2016-04-11 15:28 ` [PATCH v6 10/19] i2c: octeon: Add support for cn78xx chips Jan Glauber
2016-04-20 21:52 ` Wolfram Sang
2016-04-20 22:28 ` David Daney
2016-04-25 21:45 ` Wolfram Sang
2016-04-11 15:28 ` [PATCH v6 11/19] i2c: octeon: Flush TWSI writes with readback Jan Glauber
2016-04-11 15:28 ` [PATCH v6 12/19] i2c: octeon: Faster operation when IFLG signals late Jan Glauber
2016-04-11 15:28 ` Jan Glauber [this message]
2016-04-11 15:28 ` [PATCH v6 14/19] i2c: octeon: Move read function before write Jan Glauber
2016-04-11 15:28 ` [PATCH v6 15/19] i2c: octeon: Rename driver to prepare for split Jan Glauber
2016-04-11 15:28 ` [PATCH v6 16/19] i2c: octeon: Split the driver into two parts Jan Glauber
2016-04-11 15:28 ` [PATCH v6 17/19] i2c: thunderx: Add i2c driver for ThunderX SOC Jan Glauber
2016-04-11 15:28 ` [PATCH v6 18/19] i2c: octeon,thunderx: Move register offsets to struct Jan Glauber
2016-04-11 15:28 ` [PATCH v6 19/19] i2c: thunderx: Add smbus alert support Jan Glauber
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=3e9c18a66b449837ace80e1c86f0a6fd6a638a9d.1460387640.git.jglauber@cavium.com \
--to=jglauber@cavium.com \
--cc=david.daney@cavium.com \
--cc=ddaney@caviumnetworks.com \
--cc=linux-i2c@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=wsa@the-dreams.de \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).