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Groups > linux.kernel > #1301803

[PATCH 3.12 56/91] firewire: ohci: fix JMicron JMB38x IT context discovery

From Jiri Slaby <jslaby@suse.cz>
Newsgroups linux.kernel
Subject [PATCH 3.12 56/91] firewire: ohci: fix JMicron JMB38x IT context discovery
Date 2016-01-05 19:10 +0100
Message-ID <qNEdt-6sw-19@gated-at.bofh.it> (permalink)
References <qNDU6-65D-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

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From: Stefan Richter <stefanr@s5r6.in-berlin.de>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

commit 100ceb66d5c40cc0c7018e06a9474302470be73c upstream.

Reported by Clifford and Craig for JMicron OHCI-1394 + SDHCI combo
controllers:  Often or even most of the time, the controller is
initialized with the message "added OHCI v1.10 device as card 0, 4 IR +
0 IT contexts, quirks 0x10".  With 0 isochronous transmit DMA contexts
(IT contexts), applications like audio output are impossible.

However, OHCI-1394 demands that at least 4 IT contexts are implemented
by the link layer controller, and indeed JMicron JMB38x do implement
four of them.  Only their IsoXmitIntMask register is unreliable at early
access.

With my own JMB381 single function controller I found:
  - I can reproduce the problem with a lower probability than Craig's.
  - If I put a loop around the section which clears and reads
    IsoXmitIntMask, then either the first or the second attempt will
    return the correct initial mask of 0x0000000f.  I never encountered
    a case of needing more than a second attempt.
  - Consequently, if I put a dummy reg_read(...IsoXmitIntMaskSet)
    before the first write, the subsequent read will return the correct
    result.
  - If I merely ignore a wrong read result and force the known real
    result, later isochronous transmit DMA usage works just fine.

So let's just fix this chip bug up by the latter method.  Tested with
JMB381 on kernel 3.13 and 4.3.

Since OHCI-1394 generally requires 4 IT contexts at a minium, this
workaround is simply applied whenever the initial read of IsoXmitIntMask
returns 0, regardless whether it's a JMicron chip or not.  I never heard
of this issue together with any other chip though.

I am not 100% sure that this fix works on the OHCI-1394 part of JMB380
and JMB388 combo controllers exactly the same as on the JMB381 single-
function controller, but so far I haven't had a chance to let an owner
of a combo chip run a patched kernel.

Strangely enough, IsoRecvIntMask is always reported correctly, even
though it is probed right before IsoXmitIntMask.

Reported-by: Clifford Dunn
Reported-by: Craig Moore <craig.moore@qenos.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/firewire/ohci.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index ee805a57b72d..81b45c43a91f 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -3672,6 +3672,11 @@ static int pci_probe(struct pci_dev *dev,
 
 	reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, ~0);
 	ohci->it_context_support = reg_read(ohci, OHCI1394_IsoXmitIntMaskSet);
+	/* JMicron JMB38x often shows 0 at first read, just ignore it */
+	if (!ohci->it_context_support) {
+		ohci_notice(ohci, "overriding IsoXmitIntMask\n");
+		ohci->it_context_support = 0xf;
+	}
 	reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, ~0);
 	ohci->it_context_mask = ohci->it_context_support;
 	ohci->n_it = hweight32(ohci->it_context_mask);
-- 
2.6.4

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[PATCH 3.12 00/91] 3.12.52-stable review Jiri Slaby <jslaby@suse.cz> - 2016-01-05 18:50 +0100
  [PATCH 3.12 01/91] ipv6: fix tunnel error handling Jiri Slaby <jslaby@suse.cz> - 2016-01-05 18:50 +0100
    [PATCH 3.12 68/91] sctp: use the same clock as if sock source timestamps were on Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 73/91] net: fix IP early demux races Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 62/91] USB: cp210x: Remove CP2110 ID from compatibility list Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 81/91] ahci: add new Intel device IDs Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 75/91] skbuff: Fix offset error in skb_reorder_vlan_header Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 71/91] net: add validation for the socket syscall protocol argument Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 63/91] USB: add quirk for devices with broken LPM Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 57/91] nfs4: start callback_ident at idr 1 Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 58/91] nfs: if we have no valid attrs, then don't declare the attribute cache valid Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 74/91] vlan: Fix untag operations of stacked vlans with REORDER_HEADER off Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 48/91] netfilter: ipt_rpfilter: remove the nh_scope test in rpfilter_lookup_reverse Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 86/91] i2c: i801: add Intel Lewisburg device IDs Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 61/91] USB: serial: Another Infineon flash loader USB ID Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 51/91] ip6mr: call del_timer_sync() in ip6mr_free_table() Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 60/91] USB: cdc_acm: Ignore Infineon Flash Loader utility Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 77/91] bluetooth: Validate socket address length in sco_sock_bind(). Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 65/91] usb: Use the USB_SS_MULT() macro to decode burst multiplier for log message Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 69/91] sctp: update the netstamp_needed counter when copying sockets Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 72/91] sh_eth: fix kernel oops in skb_put() Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 64/91] USB: whci-hcd: add check for dma mapping error Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 76/91] pptp: verify sockaddr_len in pptp_bind() and pptp_connect() Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 91/91] HID: dragonrise: fix HID Descriptor for 0x0006 PID Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 87/91] cdrom: Random writing support for BD-RE media Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 70/91] ipv6: sctp: clone options to avoid use after free Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 59/91] ocfs2: fix umask ignored issue Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 67/91] atl1c: Improve driver not to do order 4 GFP_ATOMIC allocation Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 85/91] i2c: i801: Add support for Intel Broxton Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 82/91] target/stat: print full t10_wwn.model buffer Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 90/91] gpio/omap: raw read and write endian fix Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:00 +0100
    [PATCH 3.12 36/91] can: sja1000: clear interrupts on start Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 29/91] mac80211: fix driver RSSI event calculations Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 38/91] usblp: do not set TASK_INTERRUPTIBLE before lock Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 47/91] module: Call module notifier on failure after complete_formation() Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 27/91] x86/cpu: Call verify_cpu() after having entered long mode too Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 32/91] staging: rtl8712: Add device ID for Sitecom WLA2100 Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 41/91] USB: serial: option: add support for Novatel MiFi USB620L Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 56/91] firewire: ohci: fix JMicron JMB38x IT context discovery Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 46/91] tty: fix stall caused by missing memory barrier in drivers/tty/n_tty.c Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 37/91] arm64: Fix compat register mappings Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 30/91] net: mvneta: Fix CPU_MAP registers initialisation Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 26/91] x86/setup: Fix low identity map for >= 2GB kernel range Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 53/91] Btrfs: fix race leading to BUG_ON when running delalloc for nodatacow Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 55/91] ext4, jbd2: ensure entering into panic after recording an error in superblock Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 66/91] gre6: allow to update all parameters via rtnl Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 43/91] ALSA: usb-audio: add packet size quirk for the Medeli DD305 Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 54/91] ext4: fix potential use after free in __ext4_journal_stop Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 24/91] ARM: common: edma: Fix channel parameter for irq callbacks Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 14/91] net: ipmr: fix static mfc/dev leaks on table destruction Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 39/91] usb: musb: core: fix order of arguments to ulpi write callback Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 45/91] ALSA: usb-audio: work around CH345 input SysEx corruption Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 40/91] USB: ti_usb_3410_5052: Add Honeywell HGI80 ID Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 31/91] mwifiex: fix mwifiex_rdeeprom_read() Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 52/91] Btrfs: fix race leading to incorrect item deletion when dropping extents Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 33/91] Bluetooth: hidp: fix device disconnect on idle timeout Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 25/91] x86/setup: Extend low identity map to cover whole kernel range Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
      Re: [PATCH 3.12 25/91] x86/setup: Extend low identity map to cover  whole kernel range Paolo Bonzini <pbonzini@redhat.com> - 2016-01-06 11:50 +0100
        Re: [PATCH 3.12 25/91] x86/setup: Extend low identity map to cover  whole kernel range Matt Fleming <matt@codeblueprint.co.uk> - 2016-01-06 12:10 +0100
          Re: [PATCH 3.12 25/91] x86/setup: Extend low identity map to cover  whole kernel range Luis Henriques <luis.henriques@canonical.com> - 2016-01-06 12:30 +0100
            Re: [PATCH 3.12 25/91] x86/setup: Extend low identity map to cover  whole kernel range Matt Fleming <matt@codeblueprint.co.uk> - 2016-01-06 14:40 +0100
              Re: [PATCH 3.12 25/91] x86/setup: Extend low identity map to cover  whole kernel range Luis Henriques <luis.henriques@canonical.com> - 2016-01-06 15:30 +0100
                Re: [PATCH 3.12 25/91] x86/setup: Extend low identity map to cover  whole kernel range Matt Fleming <matt@codeblueprint.co.uk> - 2016-01-08 13:00 +0100
                Re: [PATCH 3.12 25/91] x86/setup: Extend low identity map to cover  whole kernel range Luis Henriques <luis.henriques@canonical.com> - 2016-01-08 14:40 +0100
                Re: [PATCH 3.12 25/91] x86/setup: Extend low identity map to cover  whole kernel range Jiri Slaby <jslaby@suse.cz> - 2016-01-09 08:10 +0100
                Re: [PATCH 3.12 25/91] x86/setup: Extend low identity map to cover  whole kernel range Kamal Mostafa <kamal@canonical.com> - 2016-01-14 22:00 +0100
    [PATCH 3.12 34/91] Bluetooth: ath3k: Add new AR3012 0930:021c id Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 44/91] ALSA: usb-audio: prevent CH345 multiport output SysEx corruption Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 35/91] Bluetooth: ath3k: Add support of AR3012 0cf3:817b device Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 28/91] x86/cpu: Fix SMAP check in PVOPS environments Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 49/91] netfilter: ip6t_SYNPROXY: fix NULL pointer dereference Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 42/91] USB: option: add XS Stick W100-2 from 4G Systems Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:10 +0100
    [PATCH 3.12 10/91] net: qmi_wwan: add XS Stick W100-2 from 4G Systems Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
    [PATCH 3.12 11/91] tcp: md5: fix lockdep annotation Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
    [PATCH 3.12 19/91] net/neighbour: fix crash at dumping device-agnostic proxy entries Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
    [PATCH 3.12 23/91] ARM: 8427/1: dma-mapping: add support for offset parameter in dma_mmap() Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
    [PATCH 3.12 07/91] packet: infer protocol from ethernet header if unset Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
    [PATCH 3.12 21/91] Bluetooth: ath3k: Add support of 04ca:300d AR3012 device Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
    [PATCH 3.12 08/91] sctp: translate host order to network order when setting a hmacid Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
    [PATCH 3.12 22/91] ARM: 8426/1: dma-mapping: add missing range check in dma_mmap() Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
    [PATCH 3.12 05/91] unix: avoid use-after-free in ep_remove_wait_queue Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
    [PATCH 3.12 02/91] MIPS: KVM: Fix ASID restoration logic Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
    [PATCH 3.12 20/91] ipv6: sctp: implement sctp_v6_destroy_sock() Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
    [PATCH 3.12 13/91] net, scm: fix PaX detected msg_controllen overflow in scm_detach_fds Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
    [PATCH 3.12 18/91] ipv6: add complete rcu protection around np->opt Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
    [PATCH 3.12 12/91] tcp: initialize tp->copied_seq in case of cross SYN connection Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
    [PATCH 3.12 04/91] MIPS: KVM: Uninit VCPU in vcpu_create error path Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
    [PATCH 3.12 06/91] packet: do skb_probe_transport_header when we actually have data Jiri Slaby <jslaby@suse.cz> - 2016-01-05 19:20 +0100
  Re: [PATCH 3.12 00/91] 3.12.52-stable review Guenter Roeck <linux@roeck-us.net> - 2016-01-05 21:50 +0100
    Re: [PATCH 3.12 00/91] 3.12.52-stable review Jiri Slaby <jslaby@suse.cz> - 2016-01-09 09:50 +0100
  Re: [PATCH 3.12 00/91] 3.12.52-stable review Shuah Khan <shuahkh@osg.samsung.com> - 2016-01-05 22:20 +0100
  Re: [PATCH 3.12 00/91] 3.12.52-stable review Nikolay Borisov <kernel@kyup.com> - 2016-01-06 08:40 +0100
    Re: [PATCH 3.12 00/91] 3.12.52-stable review Greg KH <gregkh@linuxfoundation.org> - 2016-01-06 09:20 +0100

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