linux-toradex.git/drivers/usb/host/ehci-sched.c, branch v4.2.2 Linux kernel for Apalis and Colibri modules USB: EHCI: adjust error return code 2015-01-09T17:58:49+00:00 Alan Stern stern@rowland.harvard.edu 2014-12-04T15:22:57+00:00 c401e7b4a808d50ab53ef45cb8d0b99b238bf2c9 The USB stack uses error code -ENOSPC to indicate that the periodic schedule is too full, with insufficient bandwidth to accommodate a new allocation. It uses -EFBIG to indicate that an isochronous transfer could not be linked into the schedule because it would exceed the number of isochronous packets the host controller driver can handle (generally because the new transfer would extend too far into the future). ehci-hcd uses the wrong error code at one point. This patch fixes it, along with a misleading comment and debugging message. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
The USB stack uses error code -ENOSPC to indicate that the periodic
schedule is too full, with insufficient bandwidth to accommodate a new
allocation.  It uses -EFBIG to indicate that an isochronous transfer
could not be linked into the schedule because it would exceed the
number of isochronous packets the host controller driver can handle
(generally because the new transfer would extend too far into the
future).

ehci-hcd uses the wrong error code at one point.  This patch fixes it,
along with a misleading comment and debugging message.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: EHCI: fix initialization bug in iso_stream_schedule() 2015-01-09T17:58:49+00:00 Alan Stern stern@rowland.harvard.edu 2014-12-04T15:21:56+00:00 6d89252a998a695ecb0348fc2d717dc33d90cae9 Commit c3ee9b76aa93 (EHCI: improved logic for isochronous scheduling) introduced the idea of using ehci->last_iso_frame as the origin (or base) for the circular calculations involved in modifying the isochronous schedule. However, the new code it added used ehci->last_iso_frame before the value was properly initialized. This patch rectifies the mistake by moving the initialization lines earlier in iso_stream_schedule(). This fixes Bugzilla #72891. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Fixes: c3ee9b76aa93 Reported-by: Joe Bryant <tenminjoe@yahoo.com> Tested-by: Joe Bryant <tenminjoe@yahoo.com> Tested-by: Martin Long <martin@longhome.co.uk> CC: <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Commit c3ee9b76aa93 (EHCI: improved logic for isochronous scheduling)
introduced the idea of using ehci->last_iso_frame as the origin (or
base) for the circular calculations involved in modifying the
isochronous schedule.  However, the new code it added used
ehci->last_iso_frame before the value was properly initialized.  This
patch rectifies the mistake by moving the initialization lines earlier
in iso_stream_schedule().

This fixes Bugzilla #72891.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Fixes: c3ee9b76aa93
Reported-by: Joe Bryant <tenminjoe@yahoo.com>
Tested-by: Joe Bryant <tenminjoe@yahoo.com>
Tested-by: Martin Long <martin@longhome.co.uk>
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: EHCI: fix sparse errors 2013-10-19T21:08:04+00:00 Alan Stern stern@rowland.harvard.edu 2013-10-18T15:15:14+00:00 4a71f242e51767e75c7ecdba890debab2c0dceaf This patch fixes several sparse errors in ehci-hcd introduced by commit 3d091a6f7039 (USB: EHCI: AMD periodic frame list table quirk). Although the problem fixed by that commit affects only little-endian systems, the source code has to use types appropriate for big-endian too. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
This patch fixes several sparse errors in ehci-hcd introduced by
commit 3d091a6f7039 (USB: EHCI: AMD periodic frame list table quirk).
Although the problem fixed by that commit affects only little-endian
systems, the source code has to use types appropriate for big-endian
too.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: EHCI: fix type mismatch in check_intr_schedule 2013-10-19T21:06:00+00:00 Alan Stern stern@rowland.harvard.edu 2013-10-18T15:13:08+00:00 5d8f681f3d14880d5b509eb32a910ba90ef28c36 This patch fixes a type mismatch in ehci-hcd caused by commit b35c5009bbf6 (USB: EHCI: create per-TT bandwidth tables). The c_maskp parameter in check_intr_schedule() was changed to point to unsigned int rather than __hc32, but the prototype declaration wasn't adjusted accordingly. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
This patch fixes a type mismatch in ehci-hcd caused by commit
b35c5009bbf6 (USB: EHCI: create per-TT bandwidth tables).  The c_maskp
parameter in check_intr_schedule() was changed to point to unsigned
int rather than __hc32, but the prototype declaration wasn't adjusted
accordingly.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: EHCI: start new isochronous streams ASAP 2013-10-14T18:04:38+00:00 Alan Stern stern@rowland.harvard.edu 2013-10-11T15:29:36+00:00 a393a807d0c805e7c723315ff0e88a857055e9c6 This patch changes the initial delay before the startup of a newly scheduled isochronous stream. Currently the stream doesn't start for at least 5 ms (40 microframes). This value is just an estimate; it has no real justification. Instead, we can start the stream as soon as possible after the scheduling computations are complete. Essentially this requires nothing more than reading the frame counter after the stream is scheduled, instead of before. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
This patch changes the initial delay before the startup of a newly
scheduled isochronous stream.  Currently the stream doesn't start
for at least 5 ms (40 microframes).  This value is just an estimate;
it has no real justification.

Instead, we can start the stream as soon as possible after the
scheduling computations are complete.  Essentially this requires
nothing more than reading the frame counter after the stream is
scheduled, instead of before.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: EHCI: create per-TT bandwidth tables 2013-10-14T18:04:38+00:00 Alan Stern stern@rowland.harvard.edu 2013-10-12T02:16:21+00:00 b35c5009bbf619d8885b4b3c8b102d09002acfe5 This patch continues the scheduling changes in ehci-hcd by adding a table to store the bandwidth allocation below each TT. This will speed up the scheduling code, as it will no longer need to read through the entire schedule to compute the bandwidth currently in use. Properly speaking, the FS/LS budget calculations should be done in terms of full-speed bytes per microframe, as described in the USB-2 spec. However the driver currently uses microseconds per microframe, and the scheduling code isn't robust enough at this point to change over. For the time being, we leave the calculations as they are. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
This patch continues the scheduling changes in ehci-hcd by adding a
table to store the bandwidth allocation below each TT.  This will
speed up the scheduling code, as it will no longer need to read
through the entire schedule to compute the bandwidth currently in use.

Properly speaking, the FS/LS budget calculations should be done in
terms of full-speed bytes per microframe, as described in the USB-2
spec.  However the driver currently uses microseconds per microframe,
and the scheduling code isn't robust enough at this point to change
over.  For the time being, we leave the calculations as they are.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: EHCI: use a bandwidth-allocation table 2013-10-11T23:45:43+00:00 Alan Stern stern@rowland.harvard.edu 2013-10-11T15:29:13+00:00 d0ce5c6b9208c79fc725c578eebdeb5724faf17d This patch significantly changes the scheduling code in ehci-hcd. Instead of calculating the current bandwidth utilization by trudging through the schedule and adding up the times used by the existing transfers, we will now maintain a table holding the time used for each of 64 microframes. This will drastically speed up the bandwidth computations. In addition, it eliminates a theoretical bug. An isochronous endpoint may have bandwidth reserved even at times when it has no transfers listed in the schedule. The table will keep track of the reserved bandwidth, whereas adding up entries in the schedule would miss it. As a corollary, we can keep bandwidth reserved for endpoints even when they aren't in active use. Eventually the bandwidth will be reserved when a new alternate setting is installed; for now the endpoint's reservation takes place when its first URB is submitted. A drawback of this approach is that transfers with an interval larger than 64 microframes will have to be charged for bandwidth as though the interval was 64. In practice this shouldn't matter much; transfers with longer intervals tend to be rather short anyway (things like hubs or HID devices). Another minor drawback is that we will keep track of two different period and phase values: the actual ones and the ones used for bandwidth allocation (which are limited to 64). This adds only a small amount of overhead: 3 bytes for each endpoint. The patch also adds a new debugfs file named "bandwidth" to display the information stored in the new table. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
This patch significantly changes the scheduling code in ehci-hcd.
Instead of calculating the current bandwidth utilization by trudging
through the schedule and adding up the times used by the existing
transfers, we will now maintain a table holding the time used for each
of 64 microframes.  This will drastically speed up the bandwidth
computations.

In addition, it eliminates a theoretical bug.  An isochronous endpoint
may have bandwidth reserved even at times when it has no transfers
listed in the schedule.  The table will keep track of the reserved
bandwidth, whereas adding up entries in the schedule would miss it.

As a corollary, we can keep bandwidth reserved for endpoints even
when they aren't in active use.  Eventually the bandwidth will be
reserved when a new alternate setting is installed; for now the
endpoint's reservation takes place when its first URB is submitted.

A drawback of this approach is that transfers with an interval larger
than 64 microframes will have to be charged for bandwidth as though
the interval was 64.  In practice this shouldn't matter much;
transfers with longer intervals tend to be rather short anyway (things
like hubs or HID devices).

Another minor drawback is that we will keep track of two different
period and phase values: the actual ones and the ones used for
bandwidth allocation (which are limited to 64).  This adds only a
small amount of overhead: 3 bytes for each endpoint.

The patch also adds a new debugfs file named "bandwidth" to display
the information stored in the new table.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: EHCI: create a "periodic schedule info" struct 2013-10-11T23:40:27+00:00 Alan Stern stern@rowland.harvard.edu 2013-10-11T15:29:03+00:00 ffa0248e643175cea3887c7058916af53104d8e5 This patch begins the process of unifying the scheduling parameters that ehci-hcd uses for interrupt and isochronous transfers. It creates an ehci_per_sched structure, which will be stored in both ehci_qh and ehci_iso_stream structures, and will contain the common scheduling information needed for both. Initially we merely create the new structure and move some existing fields into it. Later patches will add more fields and utilize these structures in improved scheduling algorithms. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
This patch begins the process of unifying the scheduling parameters
that ehci-hcd uses for interrupt and isochronous transfers.  It
creates an ehci_per_sched structure, which will be stored in both
ehci_qh and ehci_iso_stream structures, and will contain the common
scheduling information needed for both.

Initially we merely create the new structure and move some existing
fields into it.  Later patches will add more fields and utilize these
structures in improved scheduling algorithms.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: EHCI: use consistent NO_FRAME value 2013-10-11T23:40:26+00:00 Alan Stern stern@rowland.harvard.edu 2013-10-11T15:28:52+00:00 91a99b5e78849db90dc2f5e8dfa034af43bdb760 ehci-hcd is inconsistent in the sentinel values it uses to indicate that no frame number has been assigned for a periodic transfer. Some places it uses NO_FRAME (defined as 65535), other places it uses -1, and elsewhere it uses 9999. This patch defines a value for NO_FRAME which can fit in a 16-bit signed integer, and changes the code to use it everywhere. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
ehci-hcd is inconsistent in the sentinel values it uses to indicate
that no frame number has been assigned for a periodic transfer.  Some
places it uses NO_FRAME (defined as 65535), other places it uses -1,
and elsewhere it uses 9999.

This patch defines a value for NO_FRAME which can fit in a 16-bit
signed integer, and changes the code to use it everywhere.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: EHCI: No SSPLIT allowed in uframe 7 2013-10-11T23:37:46+00:00 Alan Stern stern@rowland.harvard.edu 2013-10-11T15:28:31+00:00 8c05dc598e5bc0eb33791de23157cf1e47cb580e The scheduling code in ehci-hcd contains an error. For full-speed isochronous-OUT transfers, the EHCI spec forbids scheduling Start-Split transactions in H-microframe 7, but the driver allows it anyway. This patch adds a check to prevent it. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
The scheduling code in ehci-hcd contains an error.  For full-speed
isochronous-OUT transfers, the EHCI spec forbids scheduling
Start-Split transactions in H-microframe 7, but the driver allows it
anyway.  This patch adds a check to prevent it.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>