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Commit 27602842060484b564cd725241b402b0bddfb830

Authored by Ming Lei
Committed by Greg Kroah-Hartman
1 parent 60dac5e284
Exists in smarc-l5.0.0_1.0.0-ga and in 5 other branches imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga

firmware loader: introduce module parameter to customize(v4) fw search path 

This patch introduces one module parameter of 'path' in firmware_class
to support customizing firmware image search path, so that people can
use its own firmware path if the default built-in paths can't meet their
demand[1], and the typical usage is passing the below from kernel command
parameter when 'firmware_class' is built in kernel:

	firmware_class.path=$CUSTOMIZED_PATH

[1], https://lkml.org/lkml/2012/10/11/337

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Showing 2 changed files with 21 additions and 1 deletions Side-by-side Diff

Documentation/firmware_class/README
Diff comments   View file @ 2760284
... ... @@ -22,11 +22,16 @@
22 22 - calls request_firmware(&fw_entry, $FIRMWARE, device)
23 23 - kernel searchs the fimware image with name $FIRMWARE directly
24 24 in the below search path of root filesystem:
  25 + User customized search path by module parameter 'path'[1]
25 26 "/lib/firmware/updates/" UTS_RELEASE,
26 27 "/lib/firmware/updates",
27 28 "/lib/firmware/" UTS_RELEASE,
28 29 "/lib/firmware"
29 30 - If found, goto 7), else goto 2)
  31 +
  32 + [1], the 'path' is a string parameter which length should be less
  33 + than 256, user should pass 'firmware_class.path=$CUSTOMIZED_PATH'
  34 + if firmware_class is built in kernel(the general situation)
30 35  
31 36 2), userspace:
32 37 - /sys/class/firmware/xxx/{loading,data} appear.
drivers/base/firmware_class.c
Diff comments   View file @ 2760284
... ... @@ -269,13 +269,23 @@
269 269 }
270 270  
271 271 /* direct firmware loading support */
272   -static const char *fw_path[] = {
  272 +static char fw_path_para[256];
  273 +static const char * const fw_path[] = {
  274 + fw_path_para,
273 275 "/lib/firmware/updates/" UTS_RELEASE,
274 276 "/lib/firmware/updates",
275 277 "/lib/firmware/" UTS_RELEASE,
276 278 "/lib/firmware"
277 279 };
278 280  
  281 +/*
  282 + * Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH'
  283 + * from kernel command line because firmware_class is generally built in
  284 + * kernel instead of module.
  285 + */
  286 +module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
  287 +MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
  288 +
279 289 /* Don't inline this: 'struct kstat' is biggish */
280 290 static noinline_for_stack long fw_file_size(struct file *file)
281 291 {
... ... @@ -317,6 +327,11 @@
317 327  
318 328 for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
319 329 struct file *file;
  330 +
  331 + /* skip the unset customized path */
  332 + if (!fw_path[i][0])
  333 + continue;
  334 +
320 335 snprintf(path, PATH_MAX, "%s/%s", fw_path[i], buf->fw_id);
321 336  
322 337 file = filp_open(path, O_RDONLY, 0);