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| author | Russell King <linux@armlinux.org.uk> | 2020-05-21 09:57:27 +0100 |
|---|---|---|
| committer | Petr Štetiar <ynezz@true.cz> | 2020-05-21 12:55:31 +0200 |
| commit | 714199ec3461b2b5bac9796d4f5ee79f56d2eb00 (patch) | |
| tree | 9d02420e261024062d56df1b12776d9594c38658 /target/linux/generic/backport-5.4/816-v5.8-i2c-pxa-avoid-complaints-with-non-responsive-slaves.patch | |
| parent | 72a1d5c3acd5b0bec46612f94bb8a82fe4d56179 (diff) | |
| download | upstream-714199ec3461b2b5bac9796d4f5ee79f56d2eb00.tar.gz upstream-714199ec3461b2b5bac9796d4f5ee79f56d2eb00.tar.bz2 upstream-714199ec3461b2b5bac9796d4f5ee79f56d2eb00.zip | |
kernel: backport v5.8 i2c-pxa updates
Add i2c-pxa updates queued for v5.8, which add bus recovery to this
driver; this is needed for the uDPU platform.
Signed-off-by: Russell King <linux@armlinux.org.uk>
Diffstat (limited to 'target/linux/generic/backport-5.4/816-v5.8-i2c-pxa-avoid-complaints-with-non-responsive-slaves.patch')
| -rw-r--r-- | target/linux/generic/backport-5.4/816-v5.8-i2c-pxa-avoid-complaints-with-non-responsive-slaves.patch | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/target/linux/generic/backport-5.4/816-v5.8-i2c-pxa-avoid-complaints-with-non-responsive-slaves.patch b/target/linux/generic/backport-5.4/816-v5.8-i2c-pxa-avoid-complaints-with-non-responsive-slaves.patch new file mode 100644 index 0000000000..308dba0fb9 --- /dev/null +++ b/target/linux/generic/backport-5.4/816-v5.8-i2c-pxa-avoid-complaints-with-non-responsive-slaves.patch @@ -0,0 +1,72 @@ +From: Russell King <rmk+kernel@armlinux.org.uk> +Bcc: linux@mail.armlinux.org.uk +Subject: [PATCH 2/7] i2c: pxa: avoid complaints with non-responsive slaves +MIME-Version: 1.0 +Content-Disposition: inline +Content-Transfer-Encoding: 8bit +Content-Type: text/plain; charset="utf-8" + +Running i2cdetect on a PXA I2C adapter is very noisy; it complains +whenever a slave fails to respond to the address cycle. Since it is +normal to probe for slaves in this way, we should not fill the kernel +log. This is especially true with SFP modules that take a while to +respond on the I2C bus, and probing via the I2C bus is the only way to +detect that they are ready. + +Fix this by changing the internal transfer return code from I2C_RETRY +to a new NO_SLAVE code (mapped to -ENXIO, as per the I2C documentation +for this condition, but we still return -EREMOTEIO to the I2C stack to +maintain long established driver behaviour.) + +Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> +--- + drivers/i2c/busses/i2c-pxa.c | 12 ++++++++---- + 1 file changed, 8 insertions(+), 4 deletions(-) + +diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c +index 46f1cf97d955..f20f8b905793 100644 +--- a/drivers/i2c/busses/i2c-pxa.c ++++ b/drivers/i2c/busses/i2c-pxa.c +@@ -90,6 +90,7 @@ + */ + #define DEF_TIMEOUT 32 + ++#define NO_SLAVE (-ENXIO) + #define BUS_ERROR (-EREMOTEIO) + #define XFER_NAKED (-ECONNREFUSED) + #define I2C_RETRY (-2000) /* an error has occurred retry transmit */ +@@ -881,7 +882,7 @@ static void i2c_pxa_irq_txempty(struct pxa_i2c *i2c, u32 isr) + */ + if (isr & ISR_ACKNAK) { + if (i2c->msg_ptr == 0 && i2c->msg_idx == 0) +- ret = I2C_RETRY; ++ ret = NO_SLAVE; + else + ret = XFER_NAKED; + } +@@ -1109,16 +1110,19 @@ static int i2c_pxa_internal_xfer(struct pxa_i2c *i2c, + { + int ret, i; + +- for (i = i2c->adap.retries; i >= 0; i--) { ++ for (i = 0; ; ) { + ret = xfer(i2c, msgs, num); +- if (ret != I2C_RETRY) ++ if (ret != I2C_RETRY && ret != NO_SLAVE) + goto out; ++ if (++i >= i2c->adap.retries) ++ break; + + if (i2c_debug) + dev_dbg(&i2c->adap.dev, "Retrying transmission\n"); + udelay(100); + } +- i2c_pxa_scream_blue_murder(i2c, "exhausted retries"); ++ if (ret != NO_SLAVE) ++ i2c_pxa_scream_blue_murder(i2c, "exhausted retries"); + ret = -EREMOTEIO; + out: + i2c_pxa_set_slave(i2c, ret); +-- +2.20.1 + |