diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.9/950-0107-i2c-bcm2835-Protect-against-unexpected-TXW-RXR-inter.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.9/950-0107-i2c-bcm2835-Protect-against-unexpected-TXW-RXR-inter.patch | 124 |
1 files changed, 0 insertions, 124 deletions
diff --git a/target/linux/brcm2708/patches-4.9/950-0107-i2c-bcm2835-Protect-against-unexpected-TXW-RXR-inter.patch b/target/linux/brcm2708/patches-4.9/950-0107-i2c-bcm2835-Protect-against-unexpected-TXW-RXR-inter.patch deleted file mode 100644 index 0d9b165aba..0000000000 --- a/target/linux/brcm2708/patches-4.9/950-0107-i2c-bcm2835-Protect-against-unexpected-TXW-RXR-inter.patch +++ /dev/null @@ -1,124 +0,0 @@ -From 8feb8081c74d15ce368baa42981ca98e77800c03 Mon Sep 17 00:00:00 2001 -From: =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= <noralf@tronnes.org> -Date: Fri, 23 Sep 2016 18:24:38 +0200 -Subject: [PATCH] i2c: bcm2835: Protect against unexpected TXW/RXR interrupts -MIME-Version: 1.0 -Content-Type: text/plain; charset=UTF-8 -Content-Transfer-Encoding: 8bit - -If an unexpected TXW or RXR interrupt occurs (msg_buf_remaining == 0), -the driver has no way to fill/drain the FIFO to stop the interrupts. -In this case the controller has to be disabled and the transfer -completed to avoid hang. - -(CLKT | ERR) and DONE interrupts are completed in their own paths, and -the controller is disabled in the transfer function after completion. -Unite the code paths and do disabling inside the interrupt routine. - -Clear interrupt status bits in the united completion path instead of -trying to do it on every interrupt which isn't necessary. -Only CLKT, ERR and DONE can be cleared that way. - -Add the status value to the error value in case of TXW/RXR errors to -distinguish them from the other S_LEN error. - -Signed-off-by: Noralf Trønnes <noralf@tronnes.org> -Reviewed-by: Eric Anholt <eric@anholt.net> ---- - drivers/i2c/busses/i2c-bcm2835.c | 40 +++++++++++++++++++++++++++++++--------- - 1 file changed, 31 insertions(+), 9 deletions(-) - ---- a/drivers/i2c/busses/i2c-bcm2835.c -+++ b/drivers/i2c/busses/i2c-bcm2835.c -@@ -50,8 +50,6 @@ - #define BCM2835_I2C_S_CLKT BIT(9) - #define BCM2835_I2C_S_LEN BIT(10) /* Fake bit for SW error reporting */ - --#define BCM2835_I2C_BITMSK_S 0x03FF -- - #define BCM2835_I2C_CDIV_MIN 0x0002 - #define BCM2835_I2C_CDIV_MAX 0xFFFE - -@@ -111,20 +109,26 @@ static void bcm2835_drain_rxfifo(struct - } - } - -+/* -+ * Note about I2C_C_CLEAR on error: -+ * The I2C_C_CLEAR on errors will take some time to resolve -- if you were in -+ * non-idle state and I2C_C_READ, it sets an abort_rx flag and runs through -+ * the state machine to send a NACK and a STOP. Since we're setting CLEAR -+ * without I2CEN, that NACK will be hanging around queued up for next time -+ * we start the engine. -+ */ -+ - static irqreturn_t bcm2835_i2c_isr(int this_irq, void *data) - { - struct bcm2835_i2c_dev *i2c_dev = data; - u32 val, err; - - val = bcm2835_i2c_readl(i2c_dev, BCM2835_I2C_S); -- val &= BCM2835_I2C_BITMSK_S; -- bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_S, val); - - err = val & (BCM2835_I2C_S_CLKT | BCM2835_I2C_S_ERR); - if (err) { - i2c_dev->msg_err = err; -- complete(&i2c_dev->completion); -- return IRQ_HANDLED; -+ goto complete; - } - - if (val & BCM2835_I2C_S_DONE) { -@@ -139,21 +143,38 @@ static irqreturn_t bcm2835_i2c_isr(int t - i2c_dev->msg_err = BCM2835_I2C_S_LEN; - else - i2c_dev->msg_err = 0; -- complete(&i2c_dev->completion); -- return IRQ_HANDLED; -+ goto complete; - } - - if (val & BCM2835_I2C_S_TXW) { -+ if (!i2c_dev->msg_buf_remaining) { -+ i2c_dev->msg_err = val | BCM2835_I2C_S_LEN; -+ goto complete; -+ } -+ - bcm2835_fill_txfifo(i2c_dev); - return IRQ_HANDLED; - } - - if (val & BCM2835_I2C_S_RXR) { -+ if (!i2c_dev->msg_buf_remaining) { -+ i2c_dev->msg_err = val | BCM2835_I2C_S_LEN; -+ goto complete; -+ } -+ - bcm2835_drain_rxfifo(i2c_dev); - return IRQ_HANDLED; - } - - return IRQ_NONE; -+ -+complete: -+ bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_C, BCM2835_I2C_C_CLEAR); -+ bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_S, BCM2835_I2C_S_CLKT | -+ BCM2835_I2C_S_ERR | BCM2835_I2C_S_DONE); -+ complete(&i2c_dev->completion); -+ -+ return IRQ_HANDLED; - } - - static int bcm2835_i2c_xfer_msg(struct bcm2835_i2c_dev *i2c_dev, -@@ -183,8 +204,9 @@ static int bcm2835_i2c_xfer_msg(struct b - - time_left = wait_for_completion_timeout(&i2c_dev->completion, - BCM2835_I2C_TIMEOUT); -- bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_C, BCM2835_I2C_C_CLEAR); - if (!time_left) { -+ bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_C, -+ BCM2835_I2C_C_CLEAR); - dev_err(i2c_dev->dev, "i2c transfer timed out\n"); - return -ETIMEDOUT; - } |