Commit be585c07dd577faac26014db4246e6d7c7a131e7
Committed by
Stefan Richter
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99692f71ee
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firewire: Add more documentation to firewire-cdev.h
Signed-off-by: Jay Fenlason <fenlason@redhat.com> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Showing 1 changed file with 7 additions and 2 deletions Side-by-side Diff
include/linux/firewire-cdev.h
... | ... | @@ -154,8 +154,13 @@ |
154 | 154 | * @request: Valid if @common.type == %FW_CDEV_EVENT_REQUEST |
155 | 155 | * @iso_interrupt: Valid if @common.type == %FW_CDEV_EVENT_ISO_INTERRUPT |
156 | 156 | * |
157 | - * Convenience union for userspace use. Events could be read(2) into a char | |
158 | - * buffer and then cast to this union for further processing. | |
157 | + * Convenience union for userspace use. Events could be read(2) into an | |
158 | + * appropriately aligned char buffer and then cast to this union for further | |
159 | + * processing. Note that for a request, response or iso_interrupt event, | |
160 | + * the data[] or header[] may make the size of the full event larger than | |
161 | + * sizeof(union fw_cdev_event). Also note that if you attempt to read(2) | |
162 | + * an event into a buffer that is not large enough for it, the data that does | |
163 | + * not fit will be discarded so that the next read(2) will return a new event. | |
159 | 164 | */ |
160 | 165 | union fw_cdev_event { |
161 | 166 | struct fw_cdev_event_common common; |