| Message ID | 20181026224910.10138-4-lyude@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915: HPD IRQ storm detection fixes | expand |
Hi Lyude,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on drm-intel/for-linux-next]
[also build test WARNING on v4.19 next-20181019]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Lyude-Paul/drm-i915-HPD-IRQ-storm-detection-fixes/20181027-085424
base: git://anongit.freedesktop.org/drm-intel for-linux-next
reproduce: make htmldocs
All warnings (new ones prefixed by >>):
include/net/mac80211.h:977: warning: Function parameter or member 'status.rates' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'status.ack_signal' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'status.ampdu_ack_len' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'status.ampdu_len' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'status.antenna' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'status.tx_time' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'status.is_valid_ack_signal' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'status.status_driver_data' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'driver_rates' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'pad' not described in 'ieee80211_tx_info'
include/net/mac80211.h:977: warning: Function parameter or member 'rate_driver_data' not described in 'ieee80211_tx_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'rx_stats_avg' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'rx_stats_avg.signal' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'rx_stats_avg.chain_signal' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'status_stats.filtered' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'status_stats.retry_failed' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'status_stats.retry_count' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'status_stats.lost_packets' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'status_stats.last_tdls_pkt_time' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'status_stats.msdu_retries' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'status_stats.msdu_failed' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'status_stats.last_ack' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'status_stats.last_ack_signal' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'status_stats.ack_signal_filled' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'status_stats.avg_ack_signal' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'tx_stats.packets' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'tx_stats.bytes' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'tx_stats.last_rate' not described in 'sta_info'
net/mac80211/sta_info.h:588: warning: Function parameter or member 'tx_stats.msdu' not described in 'sta_info'
include/linux/dma-buf.h:304: warning: Function parameter or member 'cb_excl.cb' not described in 'dma_buf'
include/linux/dma-buf.h:304: warning: Function parameter or member 'cb_excl.poll' not described in 'dma_buf'
include/linux/dma-buf.h:304: warning: Function parameter or member 'cb_excl.active' not described in 'dma_buf'
include/linux/dma-buf.h:304: warning: Function parameter or member 'cb_shared.cb' not described in 'dma_buf'
include/linux/dma-buf.h:304: warning: Function parameter or member 'cb_shared.poll' not described in 'dma_buf'
include/linux/dma-buf.h:304: warning: Function parameter or member 'cb_shared.active' not described in 'dma_buf'
include/linux/dma-fence-array.h:54: warning: Function parameter or member 'work' not described in 'dma_fence_array'
include/linux/gpio/driver.h:142: warning: Function parameter or member 'request_key' not described in 'gpio_irq_chip'
include/linux/iio/hw-consumer.h:1: warning: no structured comments found
include/linux/input/sparse-keymap.h:46: warning: Function parameter or member 'sw' not described in 'key_entry'
drivers/pci/pci.c:218: warning: Excess function parameter 'p' description in 'pci_dev_str_match_path'
include/linux/regulator/driver.h:227: warning: Function parameter or member 'resume' not described in 'regulator_ops'
drivers/regulator/core.c:4479: warning: Excess function parameter 'state' description in 'regulator_suspend'
arch/s390/include/asm/cio.h:245: warning: Function parameter or member 'esw.esw0' not described in 'irb'
arch/s390/include/asm/cio.h:245: warning: Function parameter or member 'esw.esw1' not described in 'irb'
arch/s390/include/asm/cio.h:245: warning: Function parameter or member 'esw.esw2' not described in 'irb'
arch/s390/include/asm/cio.h:245: warning: Function parameter or member 'esw.esw3' not described in 'irb'
arch/s390/include/asm/cio.h:245: warning: Function parameter or member 'esw.eadm' not described in 'irb'
drivers/slimbus/stream.c:1: warning: no structured comments found
drivers/target/target_core_device.c:1: warning: no structured comments found
drivers/usb/typec/bus.c:1: warning: no structured comments found
drivers/usb/typec/class.c:1: warning: no structured comments found
include/linux/w1.h:281: warning: Function parameter or member 'of_match_table' not described in 'w1_family'
fs/direct-io.c:257: warning: Excess function parameter 'offset' description in 'dio_complete'
fs/file_table.c:1: warning: no structured comments found
fs/libfs.c:477: warning: Excess function parameter 'available' description in 'simple_write_end'
fs/posix_acl.c:646: warning: Function parameter or member 'inode' not described in 'posix_acl_update_mode'
fs/posix_acl.c:646: warning: Function parameter or member 'mode_p' not described in 'posix_acl_update_mode'
fs/posix_acl.c:646: warning: Function parameter or member 'acl' not described in 'posix_acl_update_mode'
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c:183: warning: Function parameter or member 'blockable' not described in 'amdgpu_mn_read_lock'
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c:254: warning: Function parameter or member 'blockable' not described in 'amdgpu_mn_invalidate_range_start_gfx'
drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c:302: warning: Function parameter or member 'blockable' not described in 'amdgpu_mn_invalidate_range_start_hsa'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:382: warning: cannot understand function prototype: 'struct amdgpu_vm_pt_cursor '
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:383: warning: cannot understand function prototype: 'struct amdgpu_vm_pt_cursor '
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:554: warning: Function parameter or member 'adev' not described in 'for_each_amdgpu_vm_pt_leaf'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:554: warning: Function parameter or member 'vm' not described in 'for_each_amdgpu_vm_pt_leaf'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:554: warning: Function parameter or member 'start' not described in 'for_each_amdgpu_vm_pt_leaf'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:554: warning: Function parameter or member 'end' not described in 'for_each_amdgpu_vm_pt_leaf'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:554: warning: Function parameter or member 'cursor' not described in 'for_each_amdgpu_vm_pt_leaf'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:602: warning: Function parameter or member 'adev' not described in 'for_each_amdgpu_vm_pt_dfs_safe'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:602: warning: Function parameter or member 'vm' not described in 'for_each_amdgpu_vm_pt_dfs_safe'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:602: warning: Function parameter or member 'cursor' not described in 'for_each_amdgpu_vm_pt_dfs_safe'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:602: warning: Function parameter or member 'entry' not described in 'for_each_amdgpu_vm_pt_dfs_safe'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:847: warning: Function parameter or member 'level' not described in 'amdgpu_vm_bo_param'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1355: warning: Function parameter or member 'params' not described in 'amdgpu_vm_update_func'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1355: warning: Function parameter or member 'bo' not described in 'amdgpu_vm_update_func'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1355: warning: Function parameter or member 'pe' not described in 'amdgpu_vm_update_func'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1355: warning: Function parameter or member 'addr' not described in 'amdgpu_vm_update_func'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1355: warning: Function parameter or member 'count' not described in 'amdgpu_vm_update_func'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1355: warning: Function parameter or member 'incr' not described in 'amdgpu_vm_update_func'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1355: warning: Function parameter or member 'flags' not described in 'amdgpu_vm_update_func'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1522: warning: Function parameter or member 'params' not described in 'amdgpu_vm_update_huge'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1522: warning: Function parameter or member 'bo' not described in 'amdgpu_vm_update_huge'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1522: warning: Function parameter or member 'level' not described in 'amdgpu_vm_update_huge'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1522: warning: Function parameter or member 'pe' not described in 'amdgpu_vm_update_huge'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1522: warning: Function parameter or member 'addr' not described in 'amdgpu_vm_update_huge'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1522: warning: Function parameter or member 'count' not described in 'amdgpu_vm_update_huge'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1522: warning: Function parameter or member 'incr' not described in 'amdgpu_vm_update_huge'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:1522: warning: Function parameter or member 'flags' not described in 'amdgpu_vm_update_huge'
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c:3095: warning: Function parameter or member 'pasid' not described in 'amdgpu_vm_make_compute'
include/drm/drm_drv.h:609: warning: Function parameter or member 'gem_prime_pin' not described in 'drm_driver'
include/drm/drm_drv.h:609: warning: Function parameter or member 'gem_prime_unpin' not described in 'drm_driver'
include/drm/drm_drv.h:609: warning: Function parameter or member 'gem_prime_res_obj' not described in 'drm_driver'
include/drm/drm_drv.h:609: warning: Function parameter or member 'gem_prime_get_sg_table' not described in 'drm_driver'
include/drm/drm_drv.h:609: warning: Function parameter or member 'gem_prime_import_sg_table' not described in 'drm_driver'
include/drm/drm_drv.h:609: warning: Function parameter or member 'gem_prime_vmap' not described in 'drm_driver'
include/drm/drm_drv.h:609: warning: Function parameter or member 'gem_prime_vunmap' not described in 'drm_driver'
include/drm/drm_drv.h:609: warning: Function parameter or member 'gem_prime_mmap' not described in 'drm_driver'
include/drm/drm_mode_config.h:869: warning: Function parameter or member 'quirk_addfb_prefer_xbgr_30bpp' not described in 'drm_mode_config'
drivers/gpu/drm/drm_fourcc.c:112: warning: Function parameter or member 'dev' not described in 'drm_driver_legacy_fb_format'
drivers/gpu/drm/drm_fourcc.c:112: warning: Excess function parameter 'native' description in 'drm_driver_legacy_fb_format'
>> drivers/gpu/drm/i915/intel_hotplug.c:147: warning: Function parameter or member 'long_hpd' not described in 'intel_hpd_irq_storm_detect'
drivers/gpu/drm/i915/i915_vma.h:49: warning: cannot understand function prototype: 'struct i915_vma '
drivers/gpu/drm/i915/i915_vma.h:1: warning: no structured comments found
drivers/gpu/drm/i915/intel_guc_fwif.h:554: warning: cannot understand function prototype: 'struct guc_log_buffer_state '
drivers/gpu/drm/i915/i915_trace.h:1: warning: no structured comments found
include/linux/skbuff.h:860: warning: Function parameter or member 'dev_scratch' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'list' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'ip_defrag_offset' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'skb_mstamp' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member '__cloned_offset' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'head_frag' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member '__pkt_type_offset' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'encapsulation' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'encap_hdr_csum' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'csum_valid' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'csum_complete_sw' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'csum_level' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'inner_protocol_type' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'remcsum_offload' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'offload_fwd_mark' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'offload_mr_fwd_mark' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'sender_cpu' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'reserved_tailroom' not described in 'sk_buff'
include/linux/skbuff.h:860: warning: Function parameter or member 'inner_ipproto' not described in 'sk_buff'
include/net/sock.h:238: warning: Function parameter or member 'skc_addrpair' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_portpair' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_ipv6only' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_net_refcnt' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_v6_daddr' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_v6_rcv_saddr' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_cookie' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_listener' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_tw_dr' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_rcv_wnd' not described in 'sock_common'
include/net/sock.h:238: warning: Function parameter or member 'skc_tw_rcv_nxt' not described in 'sock_common'
include/net/sock.h:509: warning: Function parameter or member 'sk_backlog.rmem_alloc' not described in 'sock'
include/net/sock.h:509: warning: Function parameter or member 'sk_backlog.len' not described in 'sock'
include/net/sock.h:509: warning: Function parameter or member 'sk_backlog.head' not described in 'sock'
include/net/sock.h:509: warning: Function parameter or member 'sk_backlog.tail' not described in 'sock'
include/net/sock.h:509: warning: Function parameter or member 'sk_wq_raw' not described in 'sock'
include/net/sock.h:509: warning: Function parameter or member 'tcp_rtx_queue' not described in 'sock'
include/net/sock.h:509: warning: Function parameter or member 'sk_route_forced_caps' not described in 'sock'
include/net/sock.h:509: warning: Function parameter or member 'sk_txtime_report_errors' not described in 'sock'
include/net/sock.h:509: warning: Function parameter or member 'sk_validate_xmit_skb' not described in 'sock'
include/linux/netdevice.h:2018: warning: Function parameter or member 'adj_list.upper' not described in 'net_device'
include/linux/netdevice.h:2018: warning: Function parameter or member 'adj_list.lower' not described in 'net_device'
include/linux/netdevice.h:2018: warning: Function parameter or member 'gso_partial_features' not described in 'net_device'
include/linux/netdevice.h:2018: warning: Function parameter or member 'switchdev_ops' not described in 'net_device'
include/linux/netdevice.h:2018: warning: Function parameter or member 'l3mdev_ops' not described in 'net_device'
include/linux/netdevice.h:2018: warning: Function parameter or member 'xfrmdev_ops' not described in 'net_device'
include/linux/netdevice.h:2018: warning: Function parameter or member 'tlsdev_ops' not described in 'net_device'
include/linux/netdevice.h:2018: warning: Function parameter or member 'name_assign_type' not described in 'net_device'
include/linux/netdevice.h:2018: warning: Function parameter or member 'ieee802154_ptr' not described in 'net_device'
include/linux/netdevice.h:2018: warning: Function parameter or member 'mpls_ptr' not described in 'net_device'
include/linux/netdevice.h:2018: warning: Function parameter or member 'xdp_prog' not described in 'net_device'
include/linux/netdevice.h:2018: warning: Function parameter or member 'gro_flush_timeout' not described in 'net_device'
include/linux/netdevice.h:2018: warning: Function parameter or member 'nf_hooks_ingress' not described in 'net_device'
include/linux/netdevice.h:2018: warning: Function parameter or member '____cacheline_aligned_in_smp' not described in 'net_device'
include/linux/netdevice.h:2018: warning: Function parameter or member 'qdisc_hash' not described in 'net_device'
include/linux/netdevice.h:2018: warning: Function parameter or member 'xps_cpus_map' not described in 'net_device'
include/linux/netdevice.h:2018: warning: Function parameter or member 'xps_rxqs_map' not described in 'net_device'
include/linux/phylink.h:56: warning: Function parameter or member '__ETHTOOL_DECLARE_LINK_MODE_MASK(advertising' not described in 'phylink_link_state'
include/linux/phylink.h:56: warning: Function parameter or member '__ETHTOOL_DECLARE_LINK_MODE_MASK(lp_advertising' not described in 'phylink_link_state'
sound/soc/soc-core.c:2918: warning: Excess function parameter 'legacy_dai_naming' description in 'snd_soc_register_dais'
Documentation/admin-guide/cgroup-v2.rst:1485: WARNING: Block quote ends without a blank line; unexpected unindent.
Documentation/admin-guide/cgroup-v2.rst:1487: WARNING: Block quote ends without a blank line; unexpected unindent.
Documentation/admin-guide/cgroup-v2.rst:1488: WARNING: Block quote ends without a blank line; unexpected unindent.
Documentation/core-api/boot-time-mm.rst:78: ERROR: Error in "kernel-doc" directive:
unknown option: "nodocs".
vim +147 drivers/gpu/drm/i915/intel_hotplug.c
77913b39 Jani Nikula 2015-06-18 115
77913b39 Jani Nikula 2015-06-18 116 /**
beb5d089 Lyude Paul 2018-10-26 117 * intel_hpd_irq_storm_detect - gather stats and detect HPD IRQ storm on a pin
77913b39 Jani Nikula 2015-06-18 118 * @dev_priv: private driver data pointer
77913b39 Jani Nikula 2015-06-18 119 * @pin: the pin to gather stats on
77913b39 Jani Nikula 2015-06-18 120 *
beb5d089 Lyude Paul 2018-10-26 121 * Gather stats about HPD IRQs from the specified @pin, and detect IRQ
77913b39 Jani Nikula 2015-06-18 122 * storms. Only the pin specific stats and state are changed, the caller is
77913b39 Jani Nikula 2015-06-18 123 * responsible for further action.
77913b39 Jani Nikula 2015-06-18 124 *
beb5d089 Lyude Paul 2018-10-26 125 * The number of IRQs that are allowed within @HPD_STORM_DETECT_PERIOD is
317eaa95 Lyude 2017-02-03 126 * stored in @dev_priv->hotplug.hpd_storm_threshold which defaults to
beb5d089 Lyude Paul 2018-10-26 127 * @HPD_STORM_DEFAULT_THRESHOLD. Long IRQs count as +10 to this threshold, and
beb5d089 Lyude Paul 2018-10-26 128 * short IRQs count as +1. If this threshold is exceeded, it's considered an
beb5d089 Lyude Paul 2018-10-26 129 * IRQ storm and the IRQ state is set to @HPD_MARK_DISABLED.
beb5d089 Lyude Paul 2018-10-26 130 *
beb5d089 Lyude Paul 2018-10-26 131 * By default, most systems will only count long IRQs towards
beb5d089 Lyude Paul 2018-10-26 132 * &dev_priv->hotplug.hpd_storm_threshold. However, some older systems also
beb5d089 Lyude Paul 2018-10-26 133 * suffer from short IRQ storms and must also track these. Because short IRQ
beb5d089 Lyude Paul 2018-10-26 134 * storms are naturally caused by sideband interactions with DP MST devices,
beb5d089 Lyude Paul 2018-10-26 135 * short IRQ detection is only enabled for systems without DP MST support.
beb5d089 Lyude Paul 2018-10-26 136 * Systems which are new enough to support DP MST are far less likely to
beb5d089 Lyude Paul 2018-10-26 137 * suffer from IRQ storms at all, so this is fine.
317eaa95 Lyude 2017-02-03 138 *
317eaa95 Lyude 2017-02-03 139 * The HPD threshold can be controlled through i915_hpd_storm_ctl in debugfs,
317eaa95 Lyude 2017-02-03 140 * and should only be adjusted for automated hotplug testing.
77913b39 Jani Nikula 2015-06-18 141 *
beb5d089 Lyude Paul 2018-10-26 142 * Return true if an IRQ storm was detected on @pin.
77913b39 Jani Nikula 2015-06-18 143 */
77913b39 Jani Nikula 2015-06-18 144 static bool intel_hpd_irq_storm_detect(struct drm_i915_private *dev_priv,
beb5d089 Lyude Paul 2018-10-26 145 enum hpd_pin pin, bool long_hpd)
77913b39 Jani Nikula 2015-06-18 146 {
77913b39 Jani Nikula 2015-06-18 @147 unsigned long start = dev_priv->hotplug.stats[pin].last_jiffies;
77913b39 Jani Nikula 2015-06-18 148 unsigned long end = start + msecs_to_jiffies(HPD_STORM_DETECT_PERIOD);
317eaa95 Lyude 2017-02-03 149 const int threshold = dev_priv->hotplug.hpd_storm_threshold;
beb5d089 Lyude Paul 2018-10-26 150 const int increment = long_hpd ? 10 : 1;
77913b39 Jani Nikula 2015-06-18 151 bool storm = false;
77913b39 Jani Nikula 2015-06-18 152
beb5d089 Lyude Paul 2018-10-26 153 if (!long_hpd && !dev_priv->hotplug.hpd_short_storm_enabled)
beb5d089 Lyude Paul 2018-10-26 154 return false;
beb5d089 Lyude Paul 2018-10-26 155
77913b39 Jani Nikula 2015-06-18 156 if (!time_in_range(jiffies, start, end)) {
77913b39 Jani Nikula 2015-06-18 157 dev_priv->hotplug.stats[pin].last_jiffies = jiffies;
77913b39 Jani Nikula 2015-06-18 158 dev_priv->hotplug.stats[pin].count = 0;
77913b39 Jani Nikula 2015-06-18 159 DRM_DEBUG_KMS("Received HPD interrupt on PIN %d - cnt: 0\n", pin);
317eaa95 Lyude 2017-02-03 160 } else if (dev_priv->hotplug.stats[pin].count > threshold &&
317eaa95 Lyude 2017-02-03 161 threshold) {
77913b39 Jani Nikula 2015-06-18 162 dev_priv->hotplug.stats[pin].state = HPD_MARK_DISABLED;
77913b39 Jani Nikula 2015-06-18 163 DRM_DEBUG_KMS("HPD interrupt storm detected on PIN %d\n", pin);
77913b39 Jani Nikula 2015-06-18 164 storm = true;
77913b39 Jani Nikula 2015-06-18 165 } else {
beb5d089 Lyude Paul 2018-10-26 166 dev_priv->hotplug.stats[pin].count += increment;
77913b39 Jani Nikula 2015-06-18 167 DRM_DEBUG_KMS("Received HPD interrupt on PIN %d - cnt: %d\n", pin,
77913b39 Jani Nikula 2015-06-18 168 dev_priv->hotplug.stats[pin].count);
77913b39 Jani Nikula 2015-06-18 169 }
77913b39 Jani Nikula 2015-06-18 170
77913b39 Jani Nikula 2015-06-18 171 return storm;
77913b39 Jani Nikula 2015-06-18 172 }
77913b39 Jani Nikula 2015-06-18 173
:::::: The code at line 147 was first introduced by commit
:::::: 77913b39addfaa836929815515ff55cea1142b66 drm/i915: move generic hotplug code into new intel_hotplug.c file
:::::: TO: Jani Nikula <jani.nikula@intel.com>
:::::: CC: Daniel Vetter <daniel.vetter@ffwll.ch>
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
On Fri, Oct 26, 2018 at 06:49:09PM -0400, Lyude Paul wrote: > Unfortunately, it seems that the HPD IRQ storm problem from the early > days of Intel GPUs was never entirely solved, only mostly. Within the > last couple of days, I got a bug report from one of our customers who > had been having issues with their machine suddenly booting up very > slowly after having updated. The amount of time it took to boot went > from around 30 seconds, to over 6 minutes consistently. > > After some investigation, I discovered that i915 was reporting massive > amounts of short HPD IRQ spam on this system from the DisplayPort port, > despite there not being anything actually connected. The symptoms would > start with one "long" HPD IRQ being detected at boot: > > [ 1.891398] [drm:intel_get_hpd_pins [i915]] hotplug event received, stat 0x00440000, dig 0x00440000, pins 0x000000a0 > [ 1.891436] [drm:intel_hpd_irq_handler [i915]] digital hpd port B - long > [ 1.891472] [drm:intel_hpd_irq_handler [i915]] Received HPD interrupt on PIN 5 - cnt: 0 > [ 1.891508] [drm:intel_hpd_irq_handler [i915]] digital hpd port D - long > [ 1.891544] [drm:intel_hpd_irq_handler [i915]] Received HPD interrupt on PIN 7 - cnt: 0 > [ 1.891592] [drm:intel_dp_hpd_pulse [i915]] got hpd irq on port B - long > [ 1.891628] [drm:intel_dp_hpd_pulse [i915]] got hpd irq on port D - long > … > > followed by constant short IRQs afterwards: > > [ 1.895091] [drm:intel_encoder_hotplug [i915]] [CONNECTOR:66:DP-1] status updated from unknown to disconnected > [ 1.895129] [drm:i915_hotplug_work_func [i915]] Connector DP-3 (pin 7) received hotplug event. > [ 1.895165] [drm:intel_dp_detect [i915]] [CONNECTOR:72:DP-3] > [ 1.895275] [drm:intel_get_hpd_pins [i915]] hotplug event received, stat 0x00200000, dig 0x00200000, pins 0x00000080 > [ 1.895312] [drm:intel_hpd_irq_handler [i915]] digital hpd port D - short > [ 1.895762] [drm:intel_get_hpd_pins [i915]] hotplug event received, stat 0x00200000, dig 0x00200000, pins 0x00000080 > [ 1.895799] [drm:intel_hpd_irq_handler [i915]] digital hpd port D - short > [ 1.896239] [drm:intel_dp_aux_xfer [i915]] dp_aux_ch timeout status 0x71450085 > [ 1.896293] [drm:intel_get_hpd_pins [i915]] hotplug event received, stat 0x00200000, dig 0x00200000, pins 0x00000080 > [ 1.896330] [drm:intel_hpd_irq_handler [i915]] digital hpd port D - short > [ 1.896781] [drm:intel_get_hpd_pins [i915]] hotplug event received, stat 0x00200000, dig 0x00200000, pins 0x00000080 > [ 1.896817] [drm:intel_hpd_irq_handler [i915]] digital hpd port D - short > [ 1.897275] [drm:intel_get_hpd_pins [i915]] hotplug event received, stat 0x00200000, dig 0x00200000, pins 0x00000080 > > The customer's system in question has a GM45 GPU, which is apparently > well known for hotplugging storms. > > So, workaround this impressively broken hardware by changing the default > HPD storm threshold from 5 to 50. Then, make long IRQs count for 10, and > short IRQs count for 1. This makes it so that 5 long IRQs will trigger > an HPD storm, and on systems with short HPD storm detection 50 short > IRQs will trigger an HPD storm. 50 short IRQs amounts to 100ms of > constant pulsing, which seems like a good middleground between being too > sensitive and not being sensitive enough (which would cause visible > stutters in userspace every time a storm occurs). > > And just to be extra safe: we don't enable this by default on systems > with MST support. There's too high of a chance of MST support triggering > storm detection, and systems that are new enough to support MST are a > lot less likely to have issues with IRQ storms anyway. > > As a note: this patch was tested using a ThinkPad T450s and a Chamelium > to simulate the short IRQ storms. > > Changes since v1: > - Don't use two separate thresholds, just make long IRQs count for 10 > each and short IRQs count for 1. This simplifies the code a bit > - Ville Syrjälä > > Signed-off-by: Lyude Paul <lyude@redhat.com> > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> > --- > drivers/gpu/drm/i915/i915_debugfs.c | 74 ++++++++++++++++++++++++++++ > drivers/gpu/drm/i915/i915_drv.h | 5 +- > drivers/gpu/drm/i915/i915_irq.c | 7 +++ > drivers/gpu/drm/i915/intel_hotplug.c | 47 +++++++++++------- > 4 files changed, 113 insertions(+), 20 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c > index b4744a68cd88..1595b8565875 100644 > --- a/drivers/gpu/drm/i915/i915_debugfs.c > +++ b/drivers/gpu/drm/i915/i915_debugfs.c > @@ -4641,6 +4641,79 @@ static const struct file_operations i915_hpd_storm_ctl_fops = { > .write = i915_hpd_storm_ctl_write > }; > > +static int i915_hpd_short_storm_ctl_show(struct seq_file *m, void *data) > +{ > + struct drm_i915_private *dev_priv = m->private; > + > + seq_printf(m, "Enabled: %s\n", > + yesno(dev_priv->hotplug.hpd_short_storm_enabled)); > + > + return 0; > +} > + > +static int > +i915_hpd_short_storm_ctl_open(struct inode *inode, struct file *file) > +{ > + return single_open(file, i915_hpd_short_storm_ctl_show, > + inode->i_private); > +} > + > +static ssize_t i915_hpd_short_storm_ctl_write(struct file *file, > + const char __user *ubuf, > + size_t len, loff_t *offp) > +{ > + struct seq_file *m = file->private_data; > + struct drm_i915_private *dev_priv = m->private; > + struct i915_hotplug *hotplug = &dev_priv->hotplug; > + char *newline; > + char tmp[16]; > + int i; > + bool new_state; > + > + if (len >= sizeof(tmp)) > + return -EINVAL; > + > + if (copy_from_user(tmp, ubuf, len)) > + return -EFAULT; > + > + tmp[len] = '\0'; > + > + /* Strip newline, if any */ > + newline = strchr(tmp, '\n'); > + if (newline) > + *newline = '\0'; > + > + /* Reset to the "default" state for this system */ > + if (strcmp(tmp, "reset") == 0) > + new_state = !HAS_DP_MST(dev_priv); > + else if (kstrtobool(tmp, &new_state) != 0) > + return -EINVAL; > + > + DRM_DEBUG_KMS("%sabling HPD short storm detection\n", > + new_state ? "En" : "Dis"); > + > + spin_lock_irq(&dev_priv->irq_lock); > + hotplug->hpd_short_storm_enabled = new_state; > + /* Reset the HPD storm stats so we don't accidentally trigger a storm */ > + for_each_hpd_pin(i) > + hotplug->stats[i].count = 0; > + spin_unlock_irq(&dev_priv->irq_lock); > + > + /* Re-enable hpd immediately if we were in an irq storm */ > + flush_delayed_work(&dev_priv->hotplug.reenable_work); > + > + return len; > +} > + > +static const struct file_operations i915_hpd_short_storm_ctl_fops = { > + .owner = THIS_MODULE, > + .open = i915_hpd_short_storm_ctl_open, > + .read = seq_read, > + .llseek = seq_lseek, > + .release = single_release, > + .write = i915_hpd_short_storm_ctl_write, > +}; > + > static int i915_drrs_ctl_set(void *data, u64 val) > { > struct drm_i915_private *dev_priv = data; > @@ -4818,6 +4891,7 @@ static const struct i915_debugfs_files { > {"i915_guc_log_level", &i915_guc_log_level_fops}, > {"i915_guc_log_relay", &i915_guc_log_relay_fops}, > {"i915_hpd_storm_ctl", &i915_hpd_storm_ctl_fops}, > + {"i915_hpd_short_storm_ctl", &i915_hpd_short_storm_ctl_fops}, > {"i915_ipc_status", &i915_ipc_status_fops}, > {"i915_drrs_ctl", &i915_drrs_ctl_fops}, > {"i915_edp_psr_debug", &i915_edp_psr_debug_fops} > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h > index 808204a7ca7c..a378e0fd2022 100644 > --- a/drivers/gpu/drm/i915/i915_drv.h > +++ b/drivers/gpu/drm/i915/i915_drv.h > @@ -282,7 +282,8 @@ enum hpd_pin { > #define for_each_hpd_pin(__pin) \ > for ((__pin) = (HPD_NONE + 1); (__pin) < HPD_NUM_PINS; (__pin)++) > > -#define HPD_STORM_DEFAULT_THRESHOLD 5 > +/* Threshold == 5 for long IRQs, 50 for short */ > +#define HPD_STORM_DEFAULT_THRESHOLD 50 > > struct i915_hotplug { > struct work_struct hotplug_work; > @@ -307,6 +308,8 @@ struct i915_hotplug { > bool poll_enabled; > > unsigned int hpd_storm_threshold; > + /* Whether or not to count short HPD IRQs in HPD storms */ > + u8 hpd_short_storm_enabled; > > /* > * if we get a HPD irq from DP and a HPD irq from non-DP > diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c > index 10f28a2ee2e6..57970b3a22df 100644 > --- a/drivers/gpu/drm/i915/i915_irq.c > +++ b/drivers/gpu/drm/i915/i915_irq.c > @@ -4843,6 +4843,13 @@ void intel_irq_init(struct drm_i915_private *dev_priv) > dev_priv->display_irqs_enabled = false; > > dev_priv->hotplug.hpd_storm_threshold = HPD_STORM_DEFAULT_THRESHOLD; > + /* If we have MST support, we want to avoid doing short HPD IRQ storm > + * detection, as short HPD storms will occur as a natural part of > + * sideband messaging with MST. > + * On older platforms however, IRQ storms can occur with both long and > + * short pulses, as seen on some G4x systems. > + */ > + dev_priv->hotplug.hpd_short_storm_enabled = !HAS_DP_MST(dev_priv); > > dev->driver->get_vblank_timestamp = drm_calc_vbltimestamp_from_scanoutpos; > dev->driver->get_scanout_position = i915_get_crtc_scanoutpos; > diff --git a/drivers/gpu/drm/i915/intel_hotplug.c b/drivers/gpu/drm/i915/intel_hotplug.c > index 8326900a311e..aa6f52e723f0 100644 > --- a/drivers/gpu/drm/i915/intel_hotplug.c > +++ b/drivers/gpu/drm/i915/intel_hotplug.c > @@ -114,32 +114,45 @@ enum hpd_pin intel_hpd_pin_default(struct drm_i915_private *dev_priv, > #define HPD_STORM_REENABLE_DELAY (2 * 60 * 1000) > > /** > - * intel_hpd_irq_storm_detect - gather stats and detect HPD irq storm on a pin > + * intel_hpd_irq_storm_detect - gather stats and detect HPD IRQ storm on a pin > * @dev_priv: private driver data pointer > * @pin: the pin to gather stats on > * > - * Gather stats about HPD irqs from the specified @pin, and detect irq > + * Gather stats about HPD IRQs from the specified @pin, and detect IRQ > * storms. Only the pin specific stats and state are changed, the caller is > * responsible for further action. > * > - * The number of irqs that are allowed within @HPD_STORM_DETECT_PERIOD is > + * The number of IRQs that are allowed within @HPD_STORM_DETECT_PERIOD is > * stored in @dev_priv->hotplug.hpd_storm_threshold which defaults to > - * @HPD_STORM_DEFAULT_THRESHOLD. If this threshold is exceeded, it's > - * considered an irq storm and the irq state is set to @HPD_MARK_DISABLED. > + * @HPD_STORM_DEFAULT_THRESHOLD. Long IRQs count as +10 to this threshold, and > + * short IRQs count as +1. If this threshold is exceeded, it's considered an > + * IRQ storm and the IRQ state is set to @HPD_MARK_DISABLED. > + * > + * By default, most systems will only count long IRQs towards > + * &dev_priv->hotplug.hpd_storm_threshold. However, some older systems also > + * suffer from short IRQ storms and must also track these. Because short IRQ > + * storms are naturally caused by sideband interactions with DP MST devices, > + * short IRQ detection is only enabled for systems without DP MST support. > + * Systems which are new enough to support DP MST are far less likely to > + * suffer from IRQ storms at all, so this is fine. > * > * The HPD threshold can be controlled through i915_hpd_storm_ctl in debugfs, > * and should only be adjusted for automated hotplug testing. > * > - * Return true if an irq storm was detected on @pin. > + * Return true if an IRQ storm was detected on @pin. > */ > static bool intel_hpd_irq_storm_detect(struct drm_i915_private *dev_priv, > - enum hpd_pin pin) > + enum hpd_pin pin, bool long_hpd) > { > unsigned long start = dev_priv->hotplug.stats[pin].last_jiffies; > unsigned long end = start + msecs_to_jiffies(HPD_STORM_DETECT_PERIOD); > const int threshold = dev_priv->hotplug.hpd_storm_threshold; > + const int increment = long_hpd ? 10 : 1; > bool storm = false; > > + if (!long_hpd && !dev_priv->hotplug.hpd_short_storm_enabled) > + return false; > + > if (!time_in_range(jiffies, start, end)) { > dev_priv->hotplug.stats[pin].last_jiffies = jiffies; > dev_priv->hotplug.stats[pin].count = 0; > @@ -150,7 +163,7 @@ static bool intel_hpd_irq_storm_detect(struct drm_i915_private *dev_priv, > DRM_DEBUG_KMS("HPD interrupt storm detected on PIN %d\n", pin); > storm = true; > } else { > - dev_priv->hotplug.stats[pin].count++; > + dev_priv->hotplug.stats[pin].count += increment; > DRM_DEBUG_KMS("Received HPD interrupt on PIN %d - cnt: %d\n", pin, > dev_priv->hotplug.stats[pin].count); > } > @@ -405,28 +418,24 @@ void intel_hpd_irq_handler(struct drm_i915_private *dev_priv, > for_each_intel_encoder(&dev_priv->drm, encoder) { > enum hpd_pin pin = encoder->hpd_pin; > bool has_hpd_pulse = intel_encoder_has_hpd_pulse(encoder); > + bool long_hpd = true; > > if (!(BIT(pin) & pin_mask)) > continue; > > if (has_hpd_pulse) { > - bool long_hpd = long_mask & BIT(pin); > enum port port = encoder->port; > > + long_hpd = !!(long_mask & BIT(pin)); > + > DRM_DEBUG_DRIVER("digital hpd port %c - %s\n", port_name(port), > long_hpd ? "long" : "short"); > - /* > - * For long HPD pulses we want to have the digital queue happen, > - * but we still want HPD storm detection to function. > - */ > queue_dig = true; > - if (long_hpd) { > + if (long_hpd) > dev_priv->hotplug.long_port_mask |= (1 << port); > - } else { > - /* for short HPD just trigger the digital queue */ > + else > dev_priv->hotplug.short_port_mask |= (1 << port); > - continue; > - } > + > } > > if (dev_priv->hotplug.stats[pin].state == HPD_DISABLED) { > @@ -449,7 +458,7 @@ void intel_hpd_irq_handler(struct drm_i915_private *dev_priv, > queue_hp = true; > } > > - if (intel_hpd_irq_storm_detect(dev_priv, pin)) { > + if (intel_hpd_irq_storm_detect(dev_priv, pin, long_hpd)) { > dev_priv->hotplug.event_bits &= ~BIT(pin); > storm_detected = true; > } Looks like we won't actually disable the hpd irq anywhere. Even the current long hpd storm handling seems a bit confused as it will call .hpd_irq_setup() from intel_hpd_irq_handler() but actually marking the pins as disabled won't happen until i915_hotplug_work_func(). So the interrupt won't actually get disabled until the second time through intel_hpd_irq_handler() after we detected a storm.
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index b4744a68cd88..1595b8565875 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -4641,6 +4641,79 @@ static const struct file_operations i915_hpd_storm_ctl_fops = { .write = i915_hpd_storm_ctl_write }; +static int i915_hpd_short_storm_ctl_show(struct seq_file *m, void *data) +{ + struct drm_i915_private *dev_priv = m->private; + + seq_printf(m, "Enabled: %s\n", + yesno(dev_priv->hotplug.hpd_short_storm_enabled)); + + return 0; +} + +static int +i915_hpd_short_storm_ctl_open(struct inode *inode, struct file *file) +{ + return single_open(file, i915_hpd_short_storm_ctl_show, + inode->i_private); +} + +static ssize_t i915_hpd_short_storm_ctl_write(struct file *file, + const char __user *ubuf, + size_t len, loff_t *offp) +{ + struct seq_file *m = file->private_data; + struct drm_i915_private *dev_priv = m->private; + struct i915_hotplug *hotplug = &dev_priv->hotplug; + char *newline; + char tmp[16]; + int i; + bool new_state; + + if (len >= sizeof(tmp)) + return -EINVAL; + + if (copy_from_user(tmp, ubuf, len)) + return -EFAULT; + + tmp[len] = '\0'; + + /* Strip newline, if any */ + newline = strchr(tmp, '\n'); + if (newline) + *newline = '\0'; + + /* Reset to the "default" state for this system */ + if (strcmp(tmp, "reset") == 0) + new_state = !HAS_DP_MST(dev_priv); + else if (kstrtobool(tmp, &new_state) != 0) + return -EINVAL; + + DRM_DEBUG_KMS("%sabling HPD short storm detection\n", + new_state ? "En" : "Dis"); + + spin_lock_irq(&dev_priv->irq_lock); + hotplug->hpd_short_storm_enabled = new_state; + /* Reset the HPD storm stats so we don't accidentally trigger a storm */ + for_each_hpd_pin(i) + hotplug->stats[i].count = 0; + spin_unlock_irq(&dev_priv->irq_lock); + + /* Re-enable hpd immediately if we were in an irq storm */ + flush_delayed_work(&dev_priv->hotplug.reenable_work); + + return len; +} + +static const struct file_operations i915_hpd_short_storm_ctl_fops = { + .owner = THIS_MODULE, + .open = i915_hpd_short_storm_ctl_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, + .write = i915_hpd_short_storm_ctl_write, +}; + static int i915_drrs_ctl_set(void *data, u64 val) { struct drm_i915_private *dev_priv = data; @@ -4818,6 +4891,7 @@ static const struct i915_debugfs_files { {"i915_guc_log_level", &i915_guc_log_level_fops}, {"i915_guc_log_relay", &i915_guc_log_relay_fops}, {"i915_hpd_storm_ctl", &i915_hpd_storm_ctl_fops}, + {"i915_hpd_short_storm_ctl", &i915_hpd_short_storm_ctl_fops}, {"i915_ipc_status", &i915_ipc_status_fops}, {"i915_drrs_ctl", &i915_drrs_ctl_fops}, {"i915_edp_psr_debug", &i915_edp_psr_debug_fops} diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 808204a7ca7c..a378e0fd2022 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -282,7 +282,8 @@ enum hpd_pin { #define for_each_hpd_pin(__pin) \ for ((__pin) = (HPD_NONE + 1); (__pin) < HPD_NUM_PINS; (__pin)++) -#define HPD_STORM_DEFAULT_THRESHOLD 5 +/* Threshold == 5 for long IRQs, 50 for short */ +#define HPD_STORM_DEFAULT_THRESHOLD 50 struct i915_hotplug { struct work_struct hotplug_work; @@ -307,6 +308,8 @@ struct i915_hotplug { bool poll_enabled; unsigned int hpd_storm_threshold; + /* Whether or not to count short HPD IRQs in HPD storms */ + u8 hpd_short_storm_enabled; /* * if we get a HPD irq from DP and a HPD irq from non-DP diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 10f28a2ee2e6..57970b3a22df 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -4843,6 +4843,13 @@ void intel_irq_init(struct drm_i915_private *dev_priv) dev_priv->display_irqs_enabled = false; dev_priv->hotplug.hpd_storm_threshold = HPD_STORM_DEFAULT_THRESHOLD; + /* If we have MST support, we want to avoid doing short HPD IRQ storm + * detection, as short HPD storms will occur as a natural part of + * sideband messaging with MST. + * On older platforms however, IRQ storms can occur with both long and + * short pulses, as seen on some G4x systems. + */ + dev_priv->hotplug.hpd_short_storm_enabled = !HAS_DP_MST(dev_priv); dev->driver->get_vblank_timestamp = drm_calc_vbltimestamp_from_scanoutpos; dev->driver->get_scanout_position = i915_get_crtc_scanoutpos; diff --git a/drivers/gpu/drm/i915/intel_hotplug.c b/drivers/gpu/drm/i915/intel_hotplug.c index 8326900a311e..aa6f52e723f0 100644 --- a/drivers/gpu/drm/i915/intel_hotplug.c +++ b/drivers/gpu/drm/i915/intel_hotplug.c @@ -114,32 +114,45 @@ enum hpd_pin intel_hpd_pin_default(struct drm_i915_private *dev_priv, #define HPD_STORM_REENABLE_DELAY (2 * 60 * 1000) /** - * intel_hpd_irq_storm_detect - gather stats and detect HPD irq storm on a pin + * intel_hpd_irq_storm_detect - gather stats and detect HPD IRQ storm on a pin * @dev_priv: private driver data pointer * @pin: the pin to gather stats on * - * Gather stats about HPD irqs from the specified @pin, and detect irq + * Gather stats about HPD IRQs from the specified @pin, and detect IRQ * storms. Only the pin specific stats and state are changed, the caller is * responsible for further action. * - * The number of irqs that are allowed within @HPD_STORM_DETECT_PERIOD is + * The number of IRQs that are allowed within @HPD_STORM_DETECT_PERIOD is * stored in @dev_priv->hotplug.hpd_storm_threshold which defaults to - * @HPD_STORM_DEFAULT_THRESHOLD. If this threshold is exceeded, it's - * considered an irq storm and the irq state is set to @HPD_MARK_DISABLED. + * @HPD_STORM_DEFAULT_THRESHOLD. Long IRQs count as +10 to this threshold, and + * short IRQs count as +1. If this threshold is exceeded, it's considered an + * IRQ storm and the IRQ state is set to @HPD_MARK_DISABLED. + * + * By default, most systems will only count long IRQs towards + * &dev_priv->hotplug.hpd_storm_threshold. However, some older systems also + * suffer from short IRQ storms and must also track these. Because short IRQ + * storms are naturally caused by sideband interactions with DP MST devices, + * short IRQ detection is only enabled for systems without DP MST support. + * Systems which are new enough to support DP MST are far less likely to + * suffer from IRQ storms at all, so this is fine. * * The HPD threshold can be controlled through i915_hpd_storm_ctl in debugfs, * and should only be adjusted for automated hotplug testing. * - * Return true if an irq storm was detected on @pin. + * Return true if an IRQ storm was detected on @pin. */ static bool intel_hpd_irq_storm_detect(struct drm_i915_private *dev_priv, - enum hpd_pin pin) + enum hpd_pin pin, bool long_hpd) { unsigned long start = dev_priv->hotplug.stats[pin].last_jiffies; unsigned long end = start + msecs_to_jiffies(HPD_STORM_DETECT_PERIOD); const int threshold = dev_priv->hotplug.hpd_storm_threshold; + const int increment = long_hpd ? 10 : 1; bool storm = false; + if (!long_hpd && !dev_priv->hotplug.hpd_short_storm_enabled) + return false; + if (!time_in_range(jiffies, start, end)) { dev_priv->hotplug.stats[pin].last_jiffies = jiffies; dev_priv->hotplug.stats[pin].count = 0; @@ -150,7 +163,7 @@ static bool intel_hpd_irq_storm_detect(struct drm_i915_private *dev_priv, DRM_DEBUG_KMS("HPD interrupt storm detected on PIN %d\n", pin); storm = true; } else { - dev_priv->hotplug.stats[pin].count++; + dev_priv->hotplug.stats[pin].count += increment; DRM_DEBUG_KMS("Received HPD interrupt on PIN %d - cnt: %d\n", pin, dev_priv->hotplug.stats[pin].count); } @@ -405,28 +418,24 @@ void intel_hpd_irq_handler(struct drm_i915_private *dev_priv, for_each_intel_encoder(&dev_priv->drm, encoder) { enum hpd_pin pin = encoder->hpd_pin; bool has_hpd_pulse = intel_encoder_has_hpd_pulse(encoder); + bool long_hpd = true; if (!(BIT(pin) & pin_mask)) continue; if (has_hpd_pulse) { - bool long_hpd = long_mask & BIT(pin); enum port port = encoder->port; + long_hpd = !!(long_mask & BIT(pin)); + DRM_DEBUG_DRIVER("digital hpd port %c - %s\n", port_name(port), long_hpd ? "long" : "short"); - /* - * For long HPD pulses we want to have the digital queue happen, - * but we still want HPD storm detection to function. - */ queue_dig = true; - if (long_hpd) { + if (long_hpd) dev_priv->hotplug.long_port_mask |= (1 << port); - } else { - /* for short HPD just trigger the digital queue */ + else dev_priv->hotplug.short_port_mask |= (1 << port); - continue; - } + } if (dev_priv->hotplug.stats[pin].state == HPD_DISABLED) { @@ -449,7 +458,7 @@ void intel_hpd_irq_handler(struct drm_i915_private *dev_priv, queue_hp = true; } - if (intel_hpd_irq_storm_detect(dev_priv, pin)) { + if (intel_hpd_irq_storm_detect(dev_priv, pin, long_hpd)) { dev_priv->hotplug.event_bits &= ~BIT(pin); storm_detected = true; }
Unfortunately, it seems that the HPD IRQ storm problem from the early days of Intel GPUs was never entirely solved, only mostly. Within the last couple of days, I got a bug report from one of our customers who had been having issues with their machine suddenly booting up very slowly after having updated. The amount of time it took to boot went from around 30 seconds, to over 6 minutes consistently. After some investigation, I discovered that i915 was reporting massive amounts of short HPD IRQ spam on this system from the DisplayPort port, despite there not being anything actually connected. The symptoms would start with one "long" HPD IRQ being detected at boot: [ 1.891398] [drm:intel_get_hpd_pins [i915]] hotplug event received, stat 0x00440000, dig 0x00440000, pins 0x000000a0 [ 1.891436] [drm:intel_hpd_irq_handler [i915]] digital hpd port B - long [ 1.891472] [drm:intel_hpd_irq_handler [i915]] Received HPD interrupt on PIN 5 - cnt: 0 [ 1.891508] [drm:intel_hpd_irq_handler [i915]] digital hpd port D - long [ 1.891544] [drm:intel_hpd_irq_handler [i915]] Received HPD interrupt on PIN 7 - cnt: 0 [ 1.891592] [drm:intel_dp_hpd_pulse [i915]] got hpd irq on port B - long [ 1.891628] [drm:intel_dp_hpd_pulse [i915]] got hpd irq on port D - long … followed by constant short IRQs afterwards: [ 1.895091] [drm:intel_encoder_hotplug [i915]] [CONNECTOR:66:DP-1] status updated from unknown to disconnected [ 1.895129] [drm:i915_hotplug_work_func [i915]] Connector DP-3 (pin 7) received hotplug event. [ 1.895165] [drm:intel_dp_detect [i915]] [CONNECTOR:72:DP-3] [ 1.895275] [drm:intel_get_hpd_pins [i915]] hotplug event received, stat 0x00200000, dig 0x00200000, pins 0x00000080 [ 1.895312] [drm:intel_hpd_irq_handler [i915]] digital hpd port D - short [ 1.895762] [drm:intel_get_hpd_pins [i915]] hotplug event received, stat 0x00200000, dig 0x00200000, pins 0x00000080 [ 1.895799] [drm:intel_hpd_irq_handler [i915]] digital hpd port D - short [ 1.896239] [drm:intel_dp_aux_xfer [i915]] dp_aux_ch timeout status 0x71450085 [ 1.896293] [drm:intel_get_hpd_pins [i915]] hotplug event received, stat 0x00200000, dig 0x00200000, pins 0x00000080 [ 1.896330] [drm:intel_hpd_irq_handler [i915]] digital hpd port D - short [ 1.896781] [drm:intel_get_hpd_pins [i915]] hotplug event received, stat 0x00200000, dig 0x00200000, pins 0x00000080 [ 1.896817] [drm:intel_hpd_irq_handler [i915]] digital hpd port D - short [ 1.897275] [drm:intel_get_hpd_pins [i915]] hotplug event received, stat 0x00200000, dig 0x00200000, pins 0x00000080 The customer's system in question has a GM45 GPU, which is apparently well known for hotplugging storms. So, workaround this impressively broken hardware by changing the default HPD storm threshold from 5 to 50. Then, make long IRQs count for 10, and short IRQs count for 1. This makes it so that 5 long IRQs will trigger an HPD storm, and on systems with short HPD storm detection 50 short IRQs will trigger an HPD storm. 50 short IRQs amounts to 100ms of constant pulsing, which seems like a good middleground between being too sensitive and not being sensitive enough (which would cause visible stutters in userspace every time a storm occurs). And just to be extra safe: we don't enable this by default on systems with MST support. There's too high of a chance of MST support triggering storm detection, and systems that are new enough to support MST are a lot less likely to have issues with IRQ storms anyway. As a note: this patch was tested using a ThinkPad T450s and a Chamelium to simulate the short IRQ storms. Changes since v1: - Don't use two separate thresholds, just make long IRQs count for 10 each and short IRQs count for 1. This simplifies the code a bit - Ville Syrjälä Signed-off-by: Lyude Paul <lyude@redhat.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> --- drivers/gpu/drm/i915/i915_debugfs.c | 74 ++++++++++++++++++++++++++++ drivers/gpu/drm/i915/i915_drv.h | 5 +- drivers/gpu/drm/i915/i915_irq.c | 7 +++ drivers/gpu/drm/i915/intel_hotplug.c | 47 +++++++++++------- 4 files changed, 113 insertions(+), 20 deletions(-)