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staging: dwc2: fix off-by-one in check for max_packet_count parameter 

Previously, the max_packet_count could be set to 1 << x, where x is the
number of bits available (width + 4 in the code). Since 1 << x requires
x + 1 bits to represent, this will not work. The real maximum value is
(1 << x) - 1. This value is already used the default when the set value
is invalid, but the upper limit for the set value was off-by-one.

This change makes the check the same as the one for max_transfer_size,
which was already correct.

Signed-off-by: Matthijs Kooijman <matthijs@stdin.nl>
Acked-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Matthijs Kooijman 2013-08-30 18:45:12 +02:00 committed by Greg Kroah-Hartman
parent 4ab799df6d
commit 3b9edf8847
1 changed files with 1 additions and 1 deletions
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2
drivers/staging/dwc2/core.c
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@ -2209,7 +2209,7 @@ int dwc2_set_param_max_packet_count(struct dwc2_hsotg *hsotg, int val)
GHWCFG3_PACKET_SIZE_CNTR_WIDTH_MASK >> GHWCFG3_PACKET_SIZE_CNTR_WIDTH_MASK >>
GHWCFG3_PACKET_SIZE_CNTR_WIDTH_SHIFT; GHWCFG3_PACKET_SIZE_CNTR_WIDTH_SHIFT;
if (val < 15 || val > (1 << (width + 4))) if (val < 15 || val >= (1 << (width + 4)))
valid = 0; valid = 0;
if (!valid) { if (!valid) {