Merge tag 'imx-fixes-3.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/shawngu...

[cascardo/linux.git] / Documentation / printk-formats.txt

diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
index b449821..5a615c1 100644 (file)
--- a/Documentation/printk-formats.txt
+++ b/Documentation/printk-formats.txt
@@ -70,6 +70,38 @@ DMA addresses types dma_addr_t:
        For printing a dma_addr_t type which can vary based on build options,
        regardless of the width of the CPU data path. Passed by reference.
 
+Raw buffer as an escaped string:
+
+       %*pE[achnops]
+
+       For printing raw buffer as an escaped string. For the following buffer
+
+               1b 62 20 5c 43 07 22 90 0d 5d
+
+       few examples show how the conversion would be done (the result string
+       without surrounding quotes):
+
+               %*pE            "\eb \C\a"\220\r]"
+               %*pEhp          "\x1bb \C\x07"\x90\x0d]"
+               %*pEa           "\e\142\040\\\103\a\042\220\r\135"
+
+       The conversion rules are applied according to an optional combination
+       of flags (see string_escape_mem() kernel documentation for the
+       details):
+               a - ESCAPE_ANY
+               c - ESCAPE_SPECIAL
+               h - ESCAPE_HEX
+               n - ESCAPE_NULL
+               o - ESCAPE_OCTAL
+               p - ESCAPE_NP
+               s - ESCAPE_SPACE
+       By default ESCAPE_ANY_NP is used.
+
+       ESCAPE_ANY_NP is the sane choice for many cases, in particularly for
+       printing SSIDs.
+
+       If field width is omitted the 1 byte only will be escaped.
+
 Raw buffer as a hex string:
        %*ph    00 01 02  ...  3f
        %*phC   00:01:02: ... :3f