[PATCH v45 2/7] mailbox/pcc.c: ignore errors on type 4 channels.
From: Adam Young <hidden>
Date: 2026-07-21 17:53:15
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Subsystem:
acpi pcc(platform communication channel) mailbox driver, mailbox api, the rest · Maintainers:
Sudeep Holla, Jassi Brar, Linus Torvalds
THE ACPI spec states: "[The Error status register] Contains the processor relative address, represented in Generic Address Structure (GAS) format, of the Error status register. This field is ignored by the OSPM on slave channels" Referring to type 4 channels. https://uefi.org/htmlspecs/ACPI_Spec_6_4_html/14_Platform_Communications_Channel/Platform_Comm_Channel.html#hw-registers-based-communications-subspace-structure-type-5 Signed-off-by: Adam Young <redacted> --- drivers/mailbox/pcc.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c
index da26578a8aab..3c059fe87ce4 100644
--- a/drivers/mailbox/pcc.c
+++ b/drivers/mailbox/pcc.c@@ -270,6 +270,9 @@ static int pcc_mbox_error_check_and_clear(struct pcc_chan_info *pchan) u64 val; int ret; + if (pchan->type == ACPI_PCCT_TYPE_EXT_PCC_SLAVE_SUBSPACE) + return 0; + ret = pcc_chan_reg_read(&pchan->error, &val); if (ret) return ret;
--
2.43.0