diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.19/950-0422-w1-ds2408-reset-on-output_write-retry-with-readback.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.19/950-0422-w1-ds2408-reset-on-output_write-retry-with-readback.patch | 140 |
1 files changed, 0 insertions, 140 deletions
diff --git a/target/linux/brcm2708/patches-4.19/950-0422-w1-ds2408-reset-on-output_write-retry-with-readback.patch b/target/linux/brcm2708/patches-4.19/950-0422-w1-ds2408-reset-on-output_write-retry-with-readback.patch deleted file mode 100644 index afdc22e2d1..0000000000 --- a/target/linux/brcm2708/patches-4.19/950-0422-w1-ds2408-reset-on-output_write-retry-with-readback.patch +++ /dev/null @@ -1,140 +0,0 @@ -From 714580d7c11f81afb5e08c71f79a03a1ed4ae44e Mon Sep 17 00:00:00 2001 -From: Jean-Francois Dagenais <jeff.dagenais@gmail.com> -Date: Thu, 28 Mar 2019 12:41:11 -0400 -Subject: [PATCH] w1: ds2408: reset on output_write retry with readback - -commit 49695ac46861180baf2b2b92c62da8619b6bf28f upstream. - -When we have success in 'Channel Access Write' but reading back latch -states fails, a write is retried without doing a proper slave reset. -This leads to protocol errors as the slave treats the next 'Channel -Access Write' as the continuation of previous command. - -This commit is fixing this by making sure if the retry loop re-runs, a -reset is performed, whatever the failure (CONFIRM_BYTE or the read -back). - -The loop was quite due for a cleanup and this change mandated it. By -isolating the CONFIG_W1_SLAVE_DS2408_READBACK case into it's own -function, we vastly reduce the visual and branching(runtime and -compile-time) noise. - -Reported-by: Mariusz Bialonczyk <manio@skyboo.net> -Tested-by: Mariusz Bialonczyk <manio@skyboo.net> -Signed-off-by: Jean-Francois Dagenais <jeff.dagenais@gmail.com> -Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> ---- - drivers/w1/slaves/w1_ds2408.c | 76 ++++++++++++++++++----------------- - 1 file changed, 39 insertions(+), 37 deletions(-) - ---- a/drivers/w1/slaves/w1_ds2408.c -+++ b/drivers/w1/slaves/w1_ds2408.c -@@ -138,14 +138,37 @@ static ssize_t status_control_read(struc - W1_F29_REG_CONTROL_AND_STATUS, buf); - } - -+#ifdef fCONFIG_W1_SLAVE_DS2408_READBACK -+static bool optional_read_back_valid(struct w1_slave *sl, u8 expected) -+{ -+ u8 w1_buf[3]; -+ -+ if (w1_reset_resume_command(sl->master)) -+ return false; -+ -+ w1_buf[0] = W1_F29_FUNC_READ_PIO_REGS; -+ w1_buf[1] = W1_F29_REG_OUTPUT_LATCH_STATE; -+ w1_buf[2] = 0; -+ -+ w1_write_block(sl->master, w1_buf, 3); -+ -+ return (w1_read_8(sl->master) == expected); -+} -+#else -+static bool optional_read_back_valid(struct w1_slave *sl, u8 expected) -+{ -+ return true; -+} -+#endif -+ - static ssize_t output_write(struct file *filp, struct kobject *kobj, - struct bin_attribute *bin_attr, char *buf, - loff_t off, size_t count) - { - struct w1_slave *sl = kobj_to_w1_slave(kobj); - u8 w1_buf[3]; -- u8 readBack; - unsigned int retries = W1_F29_RETRIES; -+ ssize_t bytes_written = -EIO; - - if (count != 1 || off != 0) - return -EFAULT; -@@ -155,54 +178,33 @@ static ssize_t output_write(struct file - dev_dbg(&sl->dev, "mutex locked"); - - if (w1_reset_select_slave(sl)) -- goto error; -+ goto out; - -- while (retries--) { -+ do { - w1_buf[0] = W1_F29_FUNC_CHANN_ACCESS_WRITE; - w1_buf[1] = *buf; - w1_buf[2] = ~(*buf); -- w1_write_block(sl->master, w1_buf, 3); - -- readBack = w1_read_8(sl->master); -+ w1_write_block(sl->master, w1_buf, 3); - -- if (readBack != W1_F29_SUCCESS_CONFIRM_BYTE) { -- if (w1_reset_resume_command(sl->master)) -- goto error; -- /* try again, the slave is ready for a command */ -- continue; -+ if (w1_read_8(sl->master) == W1_F29_SUCCESS_CONFIRM_BYTE && -+ optional_read_back_valid(sl, *buf)) { -+ bytes_written = 1; -+ goto out; - } - --#ifdef CONFIG_W1_SLAVE_DS2408_READBACK -- /* here the master could read another byte which -- would be the PIO reg (the actual pin logic state) -- since in this driver we don't know which pins are -- in and outs, there's no value to read the state and -- compare. with (*buf) so end this command abruptly: */ - if (w1_reset_resume_command(sl->master)) -- goto error; -+ goto out; /* unrecoverable error */ -+ /* try again, the slave is ready for a command */ -+ } while (--retries); - -- /* go read back the output latches */ -- /* (the direct effect of the write above) */ -- w1_buf[0] = W1_F29_FUNC_READ_PIO_REGS; -- w1_buf[1] = W1_F29_REG_OUTPUT_LATCH_STATE; -- w1_buf[2] = 0; -- w1_write_block(sl->master, w1_buf, 3); -- /* read the result of the READ_PIO_REGS command */ -- if (w1_read_8(sl->master) == *buf) --#endif -- { -- /* success! */ -- mutex_unlock(&sl->master->bus_mutex); -- dev_dbg(&sl->dev, -- "mutex unlocked, retries:%d", retries); -- return 1; -- } -- } --error: -+out: - mutex_unlock(&sl->master->bus_mutex); -- dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries); - -- return -EIO; -+ dev_dbg(&sl->dev, "%s, mutex unlocked retries:%d\n", -+ (bytes_written > 0) ? "succeeded" : "error", retries); -+ -+ return bytes_written; - } - - |