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diff --git a/doc/release-notes/skiboot-6.0.18.rst b/doc/release-notes/skiboot-6.0.18.rst new file mode 100644 index 0000000..5465e2e --- /dev/null +++ b/doc/release-notes/skiboot-6.0.18.rst @@ -0,0 +1,184 @@ +.. _skiboot-6.0.18: + +============== +skiboot-6.0.18 +============== + +skiboot 6.0.18 was released on Wednesday March 6th, 2019. It replaces +:ref:`skiboot-6.0.17` as the current stable release in the 6.0.x series. + +It is recommended that 6.0.18 be used instead of any previous 6.0.x version +due to the bug fixes it contains. + +Over :ref:`skiboot-6.0.17` we have several bug fixes, including important ones +for powercap, ipmi-hiomap and BMC communication driver. + +powercap +======== +- powercap: occ: Fix the powercapping range allowed for user + + OCC provides two limits for minimum powercap. One being hard powercap + minimum which is guaranteed by OCC and the other one is a soft + powercap minimum which is lesser than hard-min and may or may not be + asserted due to various power-thermal reasons. So to allow the users + to access the entire powercap range, this patch exports soft powercap + minimum as the "powercap-min" DT property. And it also adds a new + DT property called "powercap-hard-min" to export the hard-min powercap + limit. + +IPMI-HIOMAP +=========== +- ipmi-hiomap test case enhancements/fixes. + +- libflash/ipmi-hiomap: Enforce message size for empty response + + The protocol defines the response to the associated messages as empty + except for the command ID and sequence fields. If the BMC is returning + extra data consider the message malformed. + +- libflash/ipmi-hiomap: Remove unused close handling + + Issuing a HIOMAP_C_CLOSE is not required by the protocol specification, + rather a close can be implicit in a subsequent + CREATE_{READ,WRITE}_WINDOW request. The implicit close provides an + opportunity to reduce LPC traffic and the implementation takes up that + optimisation, so remove the case from the IPMI callback handler. + +- libflash/ipmi-hiomap: Overhaul event handling + + Reworking the event handling was inspired by a bug report by Vasant + where the host would get wedged on multiple flash access attempts in the + face of a persistent error state on the BMC-side. The cause of this bug + was the early-exit based on ctx->update, which erronously assumed that + all events had been completely handled in prior calls to + ipmi_hiomap_handle_events(). This is not true if e.g. + HIOMAP_E_DAEMON_READY is clear in the prior calls. + + Regardless, there were other correctness and efficiency problems with + the handling strategy: + + * Ack-able event state was not restored in the face of errors in the + process of re-establishing protocol state + + * It forced needless window restoration with respect to the context in + which ipmi_hiomap_handle_events() was called. + + * Tests for HIOMAP_E_DAEMON_READY and HIOMAP_E_FLASH_LOST were redundant + with the overhauled error handling introduced in the previous patch + + Fix all of the above issues and add comments to explain the event + handling flow. + + Tests for correctness follow later in the series. + +- libflash/ipmi-hiomap: Overhaul error handling + + The aim is to improve the robustness with respect to absence of the + BMC-side daemon. The current error handling roughly mirrors what was + done for the mailbox implementation, but there's room for improvement. + + Errors are split into two classes, those that affect the transport state + and those that affect the window validity. From here, we push the + transport state error checks right to the bottom of the stack, to ensure + the link is known to be in a good state before any message is sent. + Window validity tests remain as they were in the hiomap_window_move() + and ipmi_hiomap_read() functions. Validity tests are not necessary in + the write and erase paths as we will receive an error response from the + BMC when performing a dirty or flush on an invalid window. + + Recovery also remains as it was, done on entry to the blocklevel + callbacks. If an error state is encountered in the middle of an + operation no attempt is made to recover it on the spot, instead the + error is returned up the stack and the caller can choose how it wishes + to respond. + +- libflash/ipmi-hiomap: Fix leak of msg in callback + +BMC communication +================= +- core/ipmi: Add ipmi sync messages to top of the list + + In ipmi_queue_msg_sync() path OPAL will wait until it gets response from + BMC. If we do not get response ontime we may endup in kernel hardlockups. + Hence lets add sync messages to top of the queue. This will reduces the + chance of hardlockups. + +- hw/bt: Introduce separate list for synchronous messages + + BT send logic always sends top of bt message list to BMC. Once BMC reads the + message, it clears the interrupt and bt_idle() becomes true. + + bt_add_ipmi_msg_head() adds message to top of the list. If bt message list + is not empty then: + - if bt_idle() is true then we will endup sending message to BMC before + getting response from BMC for inflight message. Looks like on some + BMC implementation this results in message timeout. + - else we endup starting message timer without actually sending message + to BMC.. which is not correct. + + This patch introduces separate list to track synchronous messages. + bt_add_ipmi_msg_head() will add messages to tail of this new list. We + will always process this queue before processing normal queue. + + Finally this patch introduces new variable (inflight_bt_msg) to track + inflight message. This will point to current inflight message. + +- hw/bt: Fix message retry handler + + In some corner cases (like BMC reboot), bt_send_and_unlock() starts + message timer, but won't send message to BMC as driver is not free to + send message. bt_expire_old_msg() function enables H2B interrupt without + actually sending message. + + This patch fixes above issue. + +- ipmi/power: Fix system reboot issue + + Kernel makes reboot/shudown OPAL call for reboot/shutdown. Once kernel + gets response from OPAL it runs opal_poll_events() until firmware + handles the request. + + On BMC based system, OPAL makes IPMI call (IPMI_CHASSIS_CONTROL) to + initiate system reboot/shutdown. At present OPAL queues IPMI messages + and return SUCESS to Host. If BMC is not ready to accept command (like + BMC reboot), then these message will fail. We have to manually + reboot/shutdown the system using BMC interface. + + This patch adds logic to validate message return value. If message failed, + then it will resend the message. At some stage BMC will be ready to accept + message and handles IPMI message. + +- hw/bt: Add backend interface to disable ipmi message retry option + + During boot OPAL makes IPMI_GET_BT_CAPS call to BMC to get BT interface + capabilities which includes IPMI message max resend count, message + timeout, etc,. Most of the time OPAL gets response from BMC within + specified timeout. In some corner cases (like mboxd daemon reset in BMC, + BMC reboot, etc) OPAL may not get response within timeout period. In + such scenarios, OPAL resends message until max resend count reaches. + + OPAL uses synchronous IPMI message (ipmi_queue_msg_sync()) for few + operations like flash read, write, etc. Thread will wait in OPAL until + it gets response from BMC. In some corner cases like BMC reboot, thread + may wait in OPAL for long time (more than 20 seconds) and results in + kernel hardlockup. + + This patch introduces new interface to disable message resend option. We + will disable message resend option for synchrous message. This will + greatly reduces kernel hardlock up issues. + + This is short term fix. Long term solution is to convert all synchronous + messages to asynhrounous one. + +PHB3 +==== +- hw/phb3/naples: Disable D-states + + Putting "Mellanox Technologies MT27700 Family [ConnectX-4] [15b3:1013]" + (more precisely, the second of 2 its PCI functions, no matter in what + order) into the D3 state causes EEH with the "PCT timeout" error. + This has been noticed on garrison machines only and firestones do not + seem to have this issue. + + This disables D-states changing for devices on root buses on Naples by + installing a config space access filter (copied from PHB4). |