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| author | Nicholas Piggin <npiggin@gmail.com> | 2018-04-10 21:49:32 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-04-25 13:24:13 +1000 |
| commit | 682e6b4da5cbe8e9a53f979a58c2a9d7dc997175 (patch) | |
| tree | 25b4eb837ae2f09cfd0ba5a54dc975fa0cfcaa92 /arch | |
| parent | 75ecfb49516c53da00c57b9efe48fa3f5504a791 (diff) | |
| download | linux-682e6b4da5cbe8e9a53f979a58c2a9d7dc997175.tar.gz linux-682e6b4da5cbe8e9a53f979a58c2a9d7dc997175.tar.bz2 linux-682e6b4da5cbe8e9a53f979a58c2a9d7dc997175.zip | |
rtc: opal: Fix OPAL RTC driver OPAL_BUSY loops
The OPAL RTC driver does not sleep in case it gets OPAL_BUSY or
OPAL_BUSY_EVENT from firmware, which causes large scheduling
latencies, up to 50 seconds have been observed here when RTC stops
responding (BMC reboot can do it).
Fix this by converting it to the standard form OPAL_BUSY loop that
sleeps.
Fixes: 628daa8d5abf ("powerpc/powernv: Add RTC and NVRAM support plus RTAS fallbacks")
Cc: stable@vger.kernel.org # v3.2+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/platforms/powernv/opal-rtc.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-rtc.c b/arch/powerpc/platforms/powernv/opal-rtc.c index f8868864f373..aa2a5139462e 100644 --- a/arch/powerpc/platforms/powernv/opal-rtc.c +++ b/arch/powerpc/platforms/powernv/opal-rtc.c @@ -48,10 +48,12 @@ unsigned long __init opal_get_boot_time(void) while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms); - if (rc == OPAL_BUSY_EVENT) + if (rc == OPAL_BUSY_EVENT) { + mdelay(OPAL_BUSY_DELAY_MS); opal_poll_events(NULL); - else if (rc == OPAL_BUSY) - mdelay(10); + } else if (rc == OPAL_BUSY) { + mdelay(OPAL_BUSY_DELAY_MS); + } } if (rc != OPAL_SUCCESS) return 0; |