Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1376099
| From | Jan Glauber <jglauber@cavium.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH v6 13/19] i2c: octeon: Add workaround for broken irqs on CN3860 |
| Date | 2016-04-11 17:40 +0200 |
| Message-ID | <rmM6v-87k-41@gated-at.bofh.it> (permalink) |
| References | <rmLWN-81T-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
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
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH v6 00/19] i2c-octeon and i2c-thunderx drivers Jan Glauber <jglauber@cavium.com> - 2016-04-11 17:30 +0200
[PATCH v6 14/19] i2c: octeon: Move read function before write Jan Glauber <jglauber@cavium.com> - 2016-04-11 17:30 +0200
[PATCH v6 06/19] i2c: octeon: Improve error status checking Jan Glauber <jglauber@cavium.com> - 2016-04-11 17:30 +0200
Re: [PATCH v6 06/19] i2c: octeon: Improve error status checking Wolfram Sang <wsa@the-dreams.de> - 2016-04-13 11:00 +0200
Re: [PATCH v6 06/19] i2c: octeon: Improve error status checking Jan Glauber <jan.glauber@caviumnetworks.com> - 2016-04-14 10:20 +0200
Re: [PATCH v6 06/19] i2c: octeon: Improve error status checking Wolfram Sang <wsa@the-dreams.de> - 2016-04-14 11:10 +0200
[PATCH v6 10/19] i2c: octeon: Add support for cn78xx chips Jan Glauber <jglauber@cavium.com> - 2016-04-11 17:30 +0200
[PATCH v6 11/19] i2c: octeon: Flush TWSI writes with readback Jan Glauber <jglauber@cavium.com> - 2016-04-11 17:40 +0200
[PATCH v6 15/19] i2c: octeon: Rename driver to prepare for split Jan Glauber <jglauber@cavium.com> - 2016-04-11 17:40 +0200
[PATCH v6 17/19] i2c: thunderx: Add i2c driver for ThunderX SOC Jan Glauber <jglauber@cavium.com> - 2016-04-11 17:40 +0200
[PATCH v6 02/19] i2c: octeon: Move set-clock and init-lowlevel upward Jan Glauber <jglauber@cavium.com> - 2016-04-11 17:40 +0200
Re: [PATCH v6 02/19] i2c: octeon: Move set-clock and init-lowlevel upward Wolfram Sang <wsa@the-dreams.de> - 2016-04-13 10:50 +0200
[PATCH v6 19/19] i2c: thunderx: Add smbus alert support Jan Glauber <jglauber@cavium.com> - 2016-04-11 17:40 +0200
[PATCH v6 03/19] i2c: octeon: Rename [read|write]_sw to reg_[read|write] Jan Glauber <jglauber@cavium.com> - 2016-04-11 17:40 +0200
Re: [PATCH v6 03/19] i2c: octeon: Rename [read|write]_sw to reg_[read|write] Wolfram Sang <wsa@the-dreams.de> - 2016-04-13 10:50 +0200
Re: [PATCH v6 03/19] i2c: octeon: Rename [read|write]_sw to reg_[read|write] Jan Glauber <jan.glauber@caviumnetworks.com> - 2016-04-14 10:00 +0200
Re: [PATCH v6 03/19] i2c: octeon: Rename [read|write]_sw to reg_[read|write] Wolfram Sang <wsa@the-dreams.de> - 2016-04-14 11:00 +0200
[PATCH v6 13/19] i2c: octeon: Add workaround for broken irqs on CN3860 Jan Glauber <jglauber@cavium.com> - 2016-04-11 17:40 +0200
[PATCH v6 07/19] i2c: octeon: Use i2c recovery framework Jan Glauber <jglauber@cavium.com> - 2016-04-11 17:40 +0200
[PATCH v6 05/19] i2c: octeon: Remove superfluous check in octeon_i2c_test_iflg Jan Glauber <jglauber@cavium.com> - 2016-04-11 17:40 +0200
Re: [PATCH v6 05/19] i2c: octeon: Remove superfluous check in octeon_i2c_test_iflg Wolfram Sang <wsa@the-dreams.de> - 2016-04-14 11:00 +0200
[PATCH v6 04/19] i2c: octeon: Introduce helper functions for register access Jan Glauber <jglauber@cavium.com> - 2016-04-11 17:40 +0200
Re: [PATCH v6 04/19] i2c: octeon: Introduce helper functions for register access Wolfram Sang <wsa@the-dreams.de> - 2016-04-13 10:50 +0200
Re: [PATCH v6 04/19] i2c: octeon: Introduce helper functions for register access Jan Glauber <jan.glauber@caviumnetworks.com> - 2016-04-14 10:20 +0200
Re: [PATCH v6 04/19] i2c: octeon: Introduce helper functions for register access Wolfram Sang <wsa@the-dreams.de> - 2016-04-14 11:00 +0200
[PATCH v6 08/19] i2c: octeon: Enable High-Level Controller Jan Glauber <jglauber@cavium.com> - 2016-04-11 17:40 +0200
csiph-web