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Diffstat (limited to 'target/linux/brcm2708/patches-3.18/0112-Fix-grabbing-lock-from-atomic-context-in-i2c-driver.patch')
-rw-r--r--target/linux/brcm2708/patches-3.18/0112-Fix-grabbing-lock-from-atomic-context-in-i2c-driver.patch219
1 files changed, 0 insertions, 219 deletions
diff --git a/target/linux/brcm2708/patches-3.18/0112-Fix-grabbing-lock-from-atomic-context-in-i2c-driver.patch b/target/linux/brcm2708/patches-3.18/0112-Fix-grabbing-lock-from-atomic-context-in-i2c-driver.patch
deleted file mode 100644
index 19484af372..0000000000
--- a/target/linux/brcm2708/patches-3.18/0112-Fix-grabbing-lock-from-atomic-context-in-i2c-driver.patch
+++ /dev/null
@@ -1,219 +0,0 @@
-From 58ee33ad32d4a00735252718f8bac3f7592af6e7 Mon Sep 17 00:00:00 2001
-From: jeanleflambeur <catalin.vasile@gmail.com>
-Date: Sun, 1 Feb 2015 12:35:38 +0100
-Subject: [PATCH 112/114] Fix grabbing lock from atomic context in i2c driver
-
-2 main changes:
-- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment:
- /* poll for transfer start bit (should only take 1-20 polls) */
- This implies that the setup function can now fail so account for this everywhere it's called
-- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock.
-
-removed dead code and update comment
-
-fixed typo in comment
----
- drivers/i2c/busses/i2c-bcm2708.c | 90 +++++++++++++++++++++++++++++-----------
- 1 file changed, 65 insertions(+), 25 deletions(-)
-
---- a/drivers/i2c/busses/i2c-bcm2708.c
-+++ b/drivers/i2c/busses/i2c-bcm2708.c
-@@ -68,6 +68,7 @@
- #define BSC_S_TA 0x00000001
-
- #define I2C_TIMEOUT_MS 150
-+#define I2C_WAIT_LOOP_COUNT 40
-
- #define DRV_NAME "bcm2708_i2c"
-
-@@ -86,6 +87,7 @@ struct bcm2708_i2c {
- void __iomem *base;
- int irq;
- struct clk *clk;
-+ u32 cdiv;
-
- struct completion done;
-
-@@ -109,10 +111,10 @@ static void bcm2708_i2c_init_pinmode(int
- int pin;
- u32 *gpio = ioremap(GPIO_BASE, SZ_16K);
-
-- BUG_ON(id != 0 && id != 1);
-+ BUG_ON(id != 0 && id != 1);
- /* BSC0 is on GPIO 0 & 1, BSC1 is on GPIO 2 & 3 */
- for (pin = id*2+0; pin <= id*2+1; pin++) {
--printk("bcm2708_i2c_init_pinmode(%d,%d)\n", id, pin);
-+ printk("bcm2708_i2c_init_pinmode(%d,%d)\n", id, pin);
- INP_GPIO(pin); /* set mode to GPIO input first */
- SET_GPIO_ALT(pin, 0); /* set mode to ALT 0 */
- }
-@@ -151,16 +153,16 @@ static inline void bcm2708_bsc_fifo_fill
- bcm2708_wr(bi, BSC_FIFO, bi->msg->buf[bi->pos++]);
- }
-
--static inline void bcm2708_bsc_setup(struct bcm2708_i2c *bi)
-+static inline int bcm2708_bsc_setup(struct bcm2708_i2c *bi)
- {
-- unsigned long bus_hz;
- u32 cdiv, s;
- u32 c = BSC_C_I2CEN | BSC_C_INTD | BSC_C_ST | BSC_C_CLEAR_1;
-+ int wait_loops = I2C_WAIT_LOOP_COUNT;
-
-- bus_hz = clk_get_rate(bi->clk);
-- cdiv = bus_hz / baudrate;
-- if (cdiv > 0xffff)
-- cdiv = 0xffff;
-+ /* Can't call clk_get_rate as it locks a mutex and here we are spinlocked.
-+ * Use the value that we cached in the probe.
-+ */
-+ cdiv = bi->cdiv;
-
- if (bi->msg->flags & I2C_M_RD)
- c |= BSC_C_INTR | BSC_C_READ;
-@@ -177,17 +179,25 @@ static inline void bcm2708_bsc_setup(str
- - Both messages to same slave address
- - Write message can fit inside FIFO (16 bytes or less) */
- if ( (bi->nmsgs > 1) &&
-- !(bi->msg[0].flags & I2C_M_RD) && (bi->msg[1].flags & I2C_M_RD) &&
-- (bi->msg[0].addr == bi->msg[1].addr) && (bi->msg[0].len <= 16)) {
-+ !(bi->msg[0].flags & I2C_M_RD) && (bi->msg[1].flags & I2C_M_RD) &&
-+ (bi->msg[0].addr == bi->msg[1].addr) && (bi->msg[0].len <= 16)) {
- /* Fill FIFO with entire write message (16 byte FIFO) */
-- while (bi->pos < bi->msg->len)
-+ while (bi->pos < bi->msg->len) {
- bcm2708_wr(bi, BSC_FIFO, bi->msg->buf[bi->pos++]);
-+ }
- /* Start write transfer (no interrupts, don't clear FIFO) */
- bcm2708_wr(bi, BSC_C, BSC_C_I2CEN | BSC_C_ST);
-+
- /* poll for transfer start bit (should only take 1-20 polls) */
- do {
- s = bcm2708_rd(bi, BSC_S);
-- } while (!(s & (BSC_S_TA | BSC_S_ERR | BSC_S_CLKT | BSC_S_DONE)));
-+ } while (!(s & (BSC_S_TA | BSC_S_ERR | BSC_S_CLKT | BSC_S_DONE)) && --wait_loops >= 0);
-+
-+ /* did we time out or some error occured? */
-+ if (wait_loops < 0 || (s & (BSC_S_ERR | BSC_S_CLKT))) {
-+ return -1;
-+ }
-+
- /* Send next read message before the write transfer finishes. */
- bi->nmsgs--;
- bi->msg++;
-@@ -197,6 +207,8 @@ static inline void bcm2708_bsc_setup(str
- }
- }
- bcm2708_wr(bi, BSC_C, c);
-+
-+ return 0;
- }
-
- static irqreturn_t bcm2708_i2c_interrupt(int irq, void *dev_id)
-@@ -204,13 +216,15 @@ static irqreturn_t bcm2708_i2c_interrupt
- struct bcm2708_i2c *bi = dev_id;
- bool handled = true;
- u32 s;
-+ int ret;
-
- spin_lock(&bi->lock);
-
- /* we may see camera interrupts on the "other" I2C channel
-- Just return if we've not sent anything */
-- if (!bi->nmsgs || !bi->msg )
-+ Just return if we've not sent anything */
-+ if (!bi->nmsgs || !bi->msg) {
- goto early_exit;
-+ }
-
- s = bcm2708_rd(bi, BSC_S);
-
-@@ -218,13 +232,16 @@ static irqreturn_t bcm2708_i2c_interrupt
- bcm2708_bsc_reset(bi);
- bi->error = true;
-
-+ bi->msg = 0; /* to inform the that all work is done */
-+ bi->nmsgs = 0;
- /* wake up our bh */
- complete(&bi->done);
- } else if (s & BSC_S_DONE) {
- bi->nmsgs--;
-
-- if (bi->msg->flags & I2C_M_RD)
-+ if (bi->msg->flags & I2C_M_RD) {
- bcm2708_bsc_fifo_drain(bi);
-+ }
-
- bcm2708_bsc_reset(bi);
-
-@@ -232,8 +249,19 @@ static irqreturn_t bcm2708_i2c_interrupt
- /* advance to next message */
- bi->msg++;
- bi->pos = 0;
-- bcm2708_bsc_setup(bi);
-+ ret = bcm2708_bsc_setup(bi);
-+ if (ret < 0) {
-+ bcm2708_bsc_reset(bi);
-+ bi->error = true;
-+ bi->msg = 0; /* to inform the that all work is done */
-+ bi->nmsgs = 0;
-+ /* wake up our bh */
-+ complete(&bi->done);
-+ goto early_exit;
-+ }
- } else {
-+ bi->msg = 0; /* to inform the that all work is done */
-+ bi->nmsgs = 0;
- /* wake up our bh */
- complete(&bi->done);
- }
-@@ -266,22 +294,33 @@ static int bcm2708_i2c_master_xfer(struc
- bi->nmsgs = num;
- bi->error = false;
-
-- bcm2708_bsc_setup(bi);
-+ ret = bcm2708_bsc_setup(bi);
-
-- /* unlockig _after_ the setup to avoid races with the interrupt routine */
- spin_unlock_irqrestore(&bi->lock, flags);
-
-- ret = wait_for_completion_timeout(&bi->done,
-- msecs_to_jiffies(I2C_TIMEOUT_MS));
-+ /* check the result of the setup */
-+ if (ret < 0)
-+ {
-+ dev_err(&adap->dev, "transfer setup timed out\n");
-+ goto error_timeout;
-+ }
-+
-+ ret = wait_for_completion_timeout(&bi->done, msecs_to_jiffies(I2C_TIMEOUT_MS));
- if (ret == 0) {
- dev_err(&adap->dev, "transfer timed out\n");
-- spin_lock_irqsave(&bi->lock, flags);
-- bcm2708_bsc_reset(bi);
-- spin_unlock_irqrestore(&bi->lock, flags);
-- return -ETIMEDOUT;
-+ goto error_timeout;
- }
-
-- return bi->error ? -EIO : num;
-+ ret = bi->error ? -EIO : num;
-+ return ret;
-+
-+error_timeout:
-+ spin_lock_irqsave(&bi->lock, flags);
-+ bcm2708_bsc_reset(bi);
-+ bi->msg = 0; /* to inform the interrupt handler that there's nothing else to be done */
-+ bi->nmsgs = 0;
-+ spin_unlock_irqrestore(&bi->lock, flags);
-+ return -ETIMEDOUT;
- }
-
- static u32 bcm2708_i2c_functionality(struct i2c_adapter *adap)
-@@ -406,6 +445,7 @@ static int bcm2708_i2c_probe(struct plat
- cdiv = 0xffff;
- baudrate = bus_hz / cdiv;
- }
-+ bi->cdiv = cdiv;
-
- dev_info(&pdev->dev, "BSC%d Controller at 0x%08lx (irq %d) (baudrate %d)\n",
- pdev->id, (unsigned long)regs->start, irq, baudrate);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-15 18:41:02 +0000