From 0555cb987ae76b53dc19e33c308e747b43622741 Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Wed, 28 Nov 2012 14:51:23 -0500 Subject: [PATCH] staging/fwserial: Limit tx/rx to 1394-2008 spec maximum Per this conversation https://lkml.org/lkml/2012/11/27/587 limit the maximum transmission to the IEEE 1394-2008 specification maximum size of 4096 bytes for asynchronous packets. Signed-off-by: Peter Hurley Acked-by: Stefan Richter Signed-off-by: Greg Kroah-Hartman --- drivers/staging/fwserial/TODO | 3 --- drivers/staging/fwserial/fwserial.c | 2 +- drivers/staging/fwserial/fwserial.h | 6 +++--- 3 files changed, 4 insertions(+), 7 deletions(-) diff --git a/drivers/staging/fwserial/TODO b/drivers/staging/fwserial/TODO index 726900548eae..ffe47d1d8c1c 100644 --- a/drivers/staging/fwserial/TODO +++ b/drivers/staging/fwserial/TODO @@ -12,9 +12,6 @@ TODOs 1. This driver uses the same unregistered vendor id that the firewire core does (0xd00d1e). Perhaps this could be exposed as a define in firewire-constants.h? -2. MAX_ASYNC_PAYLOAD needs to be publicly exposed by core/ohci - - otherwise how will this driver know the max size of address window to - open for one packet write? 3. Maybe device_max_receive() and link_speed_to_max_payload() should be taken up by the firewire core? 4. To avoid dropping rx data while still limiting the maximum buffering, diff --git a/drivers/staging/fwserial/fwserial.c b/drivers/staging/fwserial/fwserial.c index 61ee29083b26..d03a7f57e8d4 100644 --- a/drivers/staging/fwserial/fwserial.c +++ b/drivers/staging/fwserial/fwserial.c @@ -179,7 +179,7 @@ static void dump_profile(struct seq_file *m, struct stats *stats) /* Returns the max receive packet size for the given card */ static inline int device_max_receive(struct fw_device *fw_device) { - return 1 << (clamp_t(int, fw_device->max_rec, 8U, 13U) + 1); + return 1 << (clamp_t(int, fw_device->max_rec, 8U, 11U) + 1); } static void fwtty_log_tx_error(struct fwtty_port *port, int rcode) diff --git a/drivers/staging/fwserial/fwserial.h b/drivers/staging/fwserial/fwserial.h index 8b572edf9563..caa1c1ea82d5 100644 --- a/drivers/staging/fwserial/fwserial.h +++ b/drivers/staging/fwserial/fwserial.h @@ -374,10 +374,10 @@ static inline void fwtty_bind_console(struct fwtty_port *port, */ static inline int link_speed_to_max_payload(unsigned speed) { - static const int max_async[] = { 307, 614, 1229, 2458, 4916, 9832, }; - BUILD_BUG_ON(ARRAY_SIZE(max_async) - 1 != SCODE_3200); + static const int max_async[] = { 307, 614, 1229, 2458, }; + BUILD_BUG_ON(ARRAY_SIZE(max_async) - 1 != SCODE_800); - speed = clamp(speed, (unsigned) SCODE_100, (unsigned) SCODE_3200); + speed = clamp(speed, (unsigned) SCODE_100, (unsigned) SCODE_800); if (limit_bw) return max_async[speed]; else -- 2.30.2