Commit 204747c970c0d568721c76ab8a57dde0e5dcf0d5
Committed by
Lee Jones
Lee Jones
1 parent
5a78401623
Exists in
master
and in
13 other branches
mfd: kempld-core: Fix potential hang-up during boot
On PXT and COMe-cPC2 boards it is observed that the hardware mutex is acquired but not being released during initialization. This can result in a hang-up during boot if the driver is built into the kernel. Releasing the mutex twice if it was acquired fixes the problem. Subsequent request/release cycles work as expected, so the fix is only needed during initialization. Cc: <stable@vger.kernel.org> Reviewed-by: Michael Brunner <michael.brunner@kontron.com> Tested-by: Michael Brunner <michael.brunner@kontron.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Lee Jones <lee.jones@linaro.org>
Showing 1 changed file with 5 additions and 2 deletions Side-by-side Diff
drivers/mfd/kempld-core.c
| ... | ... | @@ -322,9 +322,12 @@ |
| 322 | 322 | return -ENODEV; |
| 323 | 323 | } |
| 324 | 324 | |
| 325 | - /* Release hardware mutex if aquired */ | |
| 326 | - if (!(index_reg & KEMPLD_MUTEX_KEY)) | |
| 325 | + /* Release hardware mutex if acquired */ | |
| 326 | + if (!(index_reg & KEMPLD_MUTEX_KEY)) { | |
| 327 | 327 | iowrite8(KEMPLD_MUTEX_KEY, pld->io_index); |
| 328 | + /* PXT and COMe-cPC2 boards may require a second release */ | |
| 329 | + iowrite8(KEMPLD_MUTEX_KEY, pld->io_index); | |
| 330 | + } | |
| 328 | 331 | |
| 329 | 332 | mutex_unlock(&pld->lock); |
| 330 | 333 |
