From bdd8e42dffdb81e7143e5dece0fe7fac3bb9c843 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Fri, 3 May 2013 10:18:48 -0700 Subject: [PATCH] 3.0-stable patches added patches: i2c-xiic-must-always-write-16-bit-words-to-tx_fifo.patch --- ...always-write-16-bit-words-to-tx_fifo.patch | 43 +++++++++++++++++++ queue-3.0/series | 1 + 2 files changed, 44 insertions(+) create mode 100644 queue-3.0/i2c-xiic-must-always-write-16-bit-words-to-tx_fifo.patch diff --git a/queue-3.0/i2c-xiic-must-always-write-16-bit-words-to-tx_fifo.patch b/queue-3.0/i2c-xiic-must-always-write-16-bit-words-to-tx_fifo.patch new file mode 100644 index 00000000000..207889d112c --- /dev/null +++ b/queue-3.0/i2c-xiic-must-always-write-16-bit-words-to-tx_fifo.patch @@ -0,0 +1,43 @@ +From c39e8e4354ce4daf23336de5daa28a3b01f00aa6 Mon Sep 17 00:00:00 2001 +From: "Steven A. Falco" +Date: Mon, 22 Apr 2013 09:34:39 +0000 +Subject: i2c: xiic: must always write 16-bit words to TX_FIFO + +From: "Steven A. Falco" + +commit c39e8e4354ce4daf23336de5daa28a3b01f00aa6 upstream. + +The TX_FIFO register is 10 bits wide. The lower 8 bits are the data to be +written, while the upper two bits are flags to indicate stop/start. + +The driver apparently attempted to optimize write access, by only writing a +byte in those cases where the stop/start bits are zero. However, we have +seen cases where the lower byte is duplicated onto the upper byte by the +hardware, which causes inadvertent stop/starts. + +This patch changes the write access to the transmit FIFO to always be 16 bits +wide. + +Signed off by: Steven A. Falco +Signed-off-by: Wolfram Sang +Signed-off-by: Greg Kroah-Hartman + +--- + drivers/i2c/busses/i2c-xiic.c | 6 ++---- + 1 file changed, 2 insertions(+), 4 deletions(-) + +--- a/drivers/i2c/busses/i2c-xiic.c ++++ b/drivers/i2c/busses/i2c-xiic.c +@@ -311,10 +311,8 @@ static void xiic_fill_tx_fifo(struct xii + /* last message in transfer -> STOP */ + data |= XIIC_TX_DYN_STOP_MASK; + dev_dbg(i2c->adap.dev.parent, "%s TX STOP\n", __func__); +- +- xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, data); +- } else +- xiic_setreg8(i2c, XIIC_DTR_REG_OFFSET, data); ++ } ++ xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, data); + } + } + diff --git a/queue-3.0/series b/queue-3.0/series index 3ed5acfd6e7..3785564320f 100644 --- a/queue-3.0/series +++ b/queue-3.0/series @@ -18,3 +18,4 @@ tracing-remove-most-or-all-of-stack-tracer-stack-size-from-stack_max_size.patch tracing-fix-off-by-one-on-allocating-stat-pages.patch tracing-check-return-value-of-tracing_init_dentry.patch tracing-reset-ftrace_graph_filter_enabled-if-count-is-zero.patch +i2c-xiic-must-always-write-16-bit-words-to-tx_fifo.patch -- 2.47.3