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| author | Jake Hillion <jake@hillion.co.uk> | 2025-06-05 19:09:26 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-07-10 16:08:46 +0200 |
| commit | c632f573c18c2d9174bed41c0db21aba7c7e027d (patch) | |
| tree | c8ebccce34697d45a64aba564ae39c8d6d906a2c /drivers | |
| parent | 3c0d5725b2310c28a493bfb8e7177dda1f3b9ff0 (diff) | |
| download | linux-c632f573c18c2d9174bed41c0db21aba7c7e027d.tar.gz linux-c632f573c18c2d9174bed41c0db21aba7c7e027d.tar.bz2 linux-c632f573c18c2d9174bed41c0db21aba7c7e027d.zip | |
x86/platform/amd: move final timeout check to after final sleep
[ Upstream commit f8afb12a2d7503de6558c23cacd7acbf6e9fe678 ]
__hsmp_send_message sleeps between result read attempts and has a
timeout of 100ms. Under extreme load it's possible for these sleeps to
take a long time, exceeding the 100ms. In this case the current code
does not check the register and fails with ETIMEDOUT.
Refactor the loop to ensure there is at least one read of the register
after a sleep of any duration. This removes instances of ETIMEDOUT with
a single caller, even with a misbehaving scheduler. Tested on AMD
Bergamo machines.
Suggested-by: Blaise Sanouillet <linux@blaise.sanouillet.com>
Reviewed-by: Suma Hegde <suma.hegde@amd.com>
Tested-by: Suma Hegde <suma.hegde@amd.com>
Signed-off-by: Jake Hillion <jake@hillion.co.uk>
Link: https://lore.kernel.org/r/20250605-amd-hsmp-v2-1-a811bc3dd74a@hillion.co.uk
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/platform/x86/amd/hsmp/hsmp.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/platform/x86/amd/hsmp/hsmp.c b/drivers/platform/x86/amd/hsmp/hsmp.c index a3ac09a90de4..ab877112f4c8 100644 --- a/drivers/platform/x86/amd/hsmp/hsmp.c +++ b/drivers/platform/x86/amd/hsmp/hsmp.c @@ -99,7 +99,7 @@ static int __hsmp_send_message(struct hsmp_socket *sock, struct hsmp_message *ms short_sleep = jiffies + msecs_to_jiffies(HSMP_SHORT_SLEEP); timeout = jiffies + msecs_to_jiffies(HSMP_MSG_TIMEOUT); - while (time_before(jiffies, timeout)) { + while (true) { ret = sock->amd_hsmp_rdwr(sock, mbinfo->msg_resp_off, &mbox_status, HSMP_RD); if (ret) { dev_err(sock->dev, "Error %d reading mailbox status\n", ret); @@ -108,6 +108,10 @@ static int __hsmp_send_message(struct hsmp_socket *sock, struct hsmp_message *ms if (mbox_status != HSMP_STATUS_NOT_READY) break; + + if (!time_before(jiffies, timeout)) + break; + if (time_before(jiffies, short_sleep)) usleep_range(50, 100); else |