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authorLinus Torvalds <torvalds@linux-foundation.org>2021-11-26 09:59:55 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2021-11-26 09:59:55 -0800
commit80d75202f033f51581020a5ac06699d4dff89e73 (patch)
tree6a835074bb52ba3f1586b7ebcc9f10096b7058ff
parent6b54698aec0b59943f7e8a88151bdf208de990d0 (diff)
parentbed68f4f4db429a0bf544887e64dc710e5a690ea (diff)
downloadlinux-80d75202f033f51581020a5ac06699d4dff89e73.tar.bz2
Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c fixes from Wolfram Sang: "I2C has an interrupt storm fix for the i801, better timeout handling for the new virtio driver, and some documentation fixes this time" * 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: docs: i2c: smbus-protocol: mention the repeated start condition i2c: virtio: disable timeout handling i2c: i801: Fix interrupt storm from SMB_ALERT signal i2c: i801: Restore INTREN on unload dt-bindings: i2c: imx-lpi2c: Fix i.MX 8QM compatible matching
-rw-r--r--Documentation/devicetree/bindings/i2c/i2c-imx-lpi2c.yaml5
-rw-r--r--Documentation/i2c/smbus-protocol.rst14
-rw-r--r--drivers/i2c/busses/i2c-i801.c32
-rw-r--r--drivers/i2c/busses/i2c-virtio.c14
4 files changed, 41 insertions, 24 deletions
diff --git a/Documentation/devicetree/bindings/i2c/i2c-imx-lpi2c.yaml b/Documentation/devicetree/bindings/i2c/i2c-imx-lpi2c.yaml
index 29b9447f3b84..fe0c89edf7c1 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-imx-lpi2c.yaml
+++ b/Documentation/devicetree/bindings/i2c/i2c-imx-lpi2c.yaml
@@ -17,9 +17,10 @@ properties:
oneOf:
- enum:
- fsl,imx7ulp-lpi2c
- - fsl,imx8qm-lpi2c
- items:
- - const: fsl,imx8qxp-lpi2c
+ - enum:
+ - fsl,imx8qxp-lpi2c
+ - fsl,imx8qm-lpi2c
- const: fsl,imx7ulp-lpi2c
reg:
diff --git a/Documentation/i2c/smbus-protocol.rst b/Documentation/i2c/smbus-protocol.rst
index 9e07e6bbe6a3..00d8e17d0aca 100644
--- a/Documentation/i2c/smbus-protocol.rst
+++ b/Documentation/i2c/smbus-protocol.rst
@@ -36,6 +36,8 @@ Key to symbols
=============== =============================================================
S Start condition
+Sr Repeated start condition, used to switch from write to
+ read mode.
P Stop condition
Rd/Wr (1 bit) Read/Write bit. Rd equals 1, Wr equals 0.
A, NA (1 bit) Acknowledge (ACK) and Not Acknowledge (NACK) bit
@@ -100,7 +102,7 @@ Implemented by i2c_smbus_read_byte_data()
This reads a single byte from a device, from a designated register.
The register is specified through the Comm byte::
- S Addr Wr [A] Comm [A] S Addr Rd [A] [Data] NA P
+ S Addr Wr [A] Comm [A] Sr Addr Rd [A] [Data] NA P
Functionality flag: I2C_FUNC_SMBUS_READ_BYTE_DATA
@@ -114,7 +116,7 @@ This operation is very like Read Byte; again, data is read from a
device, from a designated register that is specified through the Comm
byte. But this time, the data is a complete word (16 bits)::
- S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P
+ S Addr Wr [A] Comm [A] Sr Addr Rd [A] [DataLow] A [DataHigh] NA P
Functionality flag: I2C_FUNC_SMBUS_READ_WORD_DATA
@@ -164,7 +166,7 @@ This command selects a device register (through the Comm byte), sends
16 bits of data to it, and reads 16 bits of data in return::
S Addr Wr [A] Comm [A] DataLow [A] DataHigh [A]
- S Addr Rd [A] [DataLow] A [DataHigh] NA P
+ Sr Addr Rd [A] [DataLow] A [DataHigh] NA P
Functionality flag: I2C_FUNC_SMBUS_PROC_CALL
@@ -181,7 +183,7 @@ of data is specified by the device in the Count byte.
::
S Addr Wr [A] Comm [A]
- S Addr Rd [A] [Count] A [Data] A [Data] A ... A [Data] NA P
+ Sr Addr Rd [A] [Count] A [Data] A [Data] A ... A [Data] NA P
Functionality flag: I2C_FUNC_SMBUS_READ_BLOCK_DATA
@@ -212,7 +214,7 @@ This command selects a device register (through the Comm byte), sends
1 to 31 bytes of data to it, and reads 1 to 31 bytes of data in return::
S Addr Wr [A] Comm [A] Count [A] Data [A] ...
- S Addr Rd [A] [Count] A [Data] ... A P
+ Sr Addr Rd [A] [Count] A [Data] ... A P
Functionality flag: I2C_FUNC_SMBUS_BLOCK_PROC_CALL
@@ -300,7 +302,7 @@ This command reads a block of bytes from a device, from a
designated register that is specified through the Comm byte::
S Addr Wr [A] Comm [A]
- S Addr Rd [A] [Data] A [Data] A ... A [Data] NA P
+ Sr Addr Rd [A] [Data] A [Data] A ... A [Data] NA P
Functionality flag: I2C_FUNC_SMBUS_READ_I2C_BLOCK
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 05187457f88a..41446f9cc52d 100644
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -191,6 +191,7 @@
#define SMBSLVSTS_HST_NTFY_STS BIT(0)
/* Host Notify Command register bits */
+#define SMBSLVCMD_SMBALERT_DISABLE BIT(2)
#define SMBSLVCMD_HST_NTFY_INTREN BIT(0)
#define STATUS_ERROR_FLAGS (SMBHSTSTS_FAILED | SMBHSTSTS_BUS_ERR | \
@@ -259,6 +260,7 @@ struct i801_priv {
struct i2c_adapter adapter;
unsigned long smba;
unsigned char original_hstcfg;
+ unsigned char original_hstcnt;
unsigned char original_slvcmd;
struct pci_dev *pci_dev;
unsigned int features;
@@ -641,12 +643,20 @@ static irqreturn_t i801_isr(int irq, void *dev_id)
i801_isr_byte_done(priv);
/*
- * Clear irq sources and report transaction result.
+ * Clear remaining IRQ sources: Completion of last command, errors
+ * and the SMB_ALERT signal. SMB_ALERT status is set after signal
+ * assertion independently of the interrupt generation being blocked
+ * or not so clear it always when the status is set.
+ */
+ status &= SMBHSTSTS_INTR | STATUS_ERROR_FLAGS | SMBHSTSTS_SMBALERT_STS;
+ if (status)
+ outb_p(status, SMBHSTSTS(priv));
+ status &= ~SMBHSTSTS_SMBALERT_STS; /* SMB_ALERT not reported */
+ /*
+ * Report transaction result.
* ->status must be cleared before the next transaction is started.
*/
- status &= SMBHSTSTS_INTR | STATUS_ERROR_FLAGS;
if (status) {
- outb_p(status, SMBHSTSTS(priv));
priv->status = status;
complete(&priv->done);
}
@@ -974,9 +984,13 @@ static void i801_enable_host_notify(struct i2c_adapter *adapter)
if (!(priv->features & FEATURE_HOST_NOTIFY))
return;
- if (!(SMBSLVCMD_HST_NTFY_INTREN & priv->original_slvcmd))
- outb_p(SMBSLVCMD_HST_NTFY_INTREN | priv->original_slvcmd,
- SMBSLVCMD(priv));
+ /*
+ * Enable host notify interrupt and block the generation of interrupt
+ * from the SMB_ALERT signal because the driver does not support
+ * SMBus Alert.
+ */
+ outb_p(SMBSLVCMD_HST_NTFY_INTREN | SMBSLVCMD_SMBALERT_DISABLE |
+ priv->original_slvcmd, SMBSLVCMD(priv));
/* clear Host Notify bit to allow a new notification */
outb_p(SMBSLVSTS_HST_NTFY_STS, SMBSLVSTS(priv));
@@ -1805,7 +1819,8 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
outb_p(inb_p(SMBAUXCTL(priv)) &
~(SMBAUXCTL_CRC | SMBAUXCTL_E32B), SMBAUXCTL(priv));
- /* Remember original Host Notify setting */
+ /* Remember original Interrupt and Host Notify settings */
+ priv->original_hstcnt = inb_p(SMBHSTCNT(priv)) & ~SMBHSTCNT_KILL;
if (priv->features & FEATURE_HOST_NOTIFY)
priv->original_slvcmd = inb_p(SMBSLVCMD(priv));
@@ -1869,6 +1884,7 @@ static void i801_remove(struct pci_dev *dev)
{
struct i801_priv *priv = pci_get_drvdata(dev);
+ outb_p(priv->original_hstcnt, SMBHSTCNT(priv));
i801_disable_host_notify(priv);
i801_del_mux(priv);
i2c_del_adapter(&priv->adapter);
@@ -1892,6 +1908,7 @@ static void i801_shutdown(struct pci_dev *dev)
struct i801_priv *priv = pci_get_drvdata(dev);
/* Restore config registers to avoid hard hang on some systems */
+ outb_p(priv->original_hstcnt, SMBHSTCNT(priv));
i801_disable_host_notify(priv);
pci_write_config_byte(dev, SMBHSTCFG, priv->original_hstcfg);
}
@@ -1901,6 +1918,7 @@ static int i801_suspend(struct device *dev)
{
struct i801_priv *priv = dev_get_drvdata(dev);
+ outb_p(priv->original_hstcnt, SMBHSTCNT(priv));
pci_write_config_byte(priv->pci_dev, SMBHSTCFG, priv->original_hstcfg);
return 0;
}
diff --git a/drivers/i2c/busses/i2c-virtio.c b/drivers/i2c/busses/i2c-virtio.c
index 1ed4daa918a0..95378780da6d 100644
--- a/drivers/i2c/busses/i2c-virtio.c
+++ b/drivers/i2c/busses/i2c-virtio.c
@@ -104,11 +104,10 @@ static int virtio_i2c_prepare_reqs(struct virtqueue *vq,
static int virtio_i2c_complete_reqs(struct virtqueue *vq,
struct virtio_i2c_req *reqs,
- struct i2c_msg *msgs, int num,
- bool timedout)
+ struct i2c_msg *msgs, int num)
{
struct virtio_i2c_req *req;
- bool failed = timedout;
+ bool failed = false;
unsigned int len;
int i, j = 0;
@@ -130,7 +129,7 @@ static int virtio_i2c_complete_reqs(struct virtqueue *vq,
j++;
}
- return timedout ? -ETIMEDOUT : j;
+ return j;
}
static int virtio_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
@@ -139,7 +138,6 @@ static int virtio_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
struct virtio_i2c *vi = i2c_get_adapdata(adap);
struct virtqueue *vq = vi->vq;
struct virtio_i2c_req *reqs;
- unsigned long time_left;
int count;
reqs = kcalloc(num, sizeof(*reqs), GFP_KERNEL);
@@ -162,11 +160,9 @@ static int virtio_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
reinit_completion(&vi->completion);
virtqueue_kick(vq);
- time_left = wait_for_completion_timeout(&vi->completion, adap->timeout);
- if (!time_left)
- dev_err(&adap->dev, "virtio i2c backend timeout.\n");
+ wait_for_completion(&vi->completion);
- count = virtio_i2c_complete_reqs(vq, reqs, msgs, count, !time_left);
+ count = virtio_i2c_complete_reqs(vq, reqs, msgs, count);
err_free:
kfree(reqs);