Hello
If you use usb buffers from the state you will need add lock in order to
protect concurrent access to buffer. There may have multiple concurrent
operations from rc-polling/demux/frontend. Lets say you are reading ber
and it sets data to buffer (state), then context switch to remote
controller polling => buffer in state is overwritten, then context is
changed back to ber reading and now there is bad data.
regards
Antti
On 10/07/2016 08:24 PM, Mauro Carvalho Chehab wrote:
Sending URB control messages from stack was never supported. Yet, on x86,
the stack was usually at a memory region that allows DMA transfer.
So, several drivers got it wrong. On Kernel 4.9, if VMAP_STACK=y, none of
those drivers will work, as the stack won't be on a DMA-able area anymore.
So, fix the dvb-usb drivers that requre it.
Please notice that, while all those patches compile, I don't have devices
using those drivers to test. So, I really appreciate if people with devices
using those drivers could test and report if they don't break anything.
Thanks!
Mauro
Mauro Carvalho Chehab (26):
af9005: don't do DMA on stack
cinergyT2-core: don't do DMA on stack
cinergyT2-core:: handle error code on RC query
cinergyT2-fe: cache stats at cinergyt2_fe_read_status()
cinergyT2-fe: don't do DMA on stack
cxusb: don't do DMA on stack
dib0700: be sure that dib0700_ctrl_rd() users can do DMA
dib0700_core: don't use stack on I2C reads
dibusb: don't do DMA on stack
dibusb: handle error code on RC query
digitv: don't do DMA on stack
dtt200u-fe: don't do DMA on stack
dtt200u-fe: handle errors on USB control messages
dtt200u: don't do DMA on stack
dtt200u: handle USB control message errors
dtv5100: : don't do DMA on stack
gp8psk: don't do DMA on stack
gp8psk: don't go past the buffer size
nova-t-usb2: don't do DMA on stack
pctv452e: don't do DMA on stack
pctv452e: don't call BUG_ON() on non-fatal error
technisat-usb2: use DMA buffers for I2C transfers
dvb-usb: warn if return value for USB read/write routines is not
checked
nova-t-usb2: handle error code on RC query
dw2102: return error if su3000_power_ctrl() fails
digitv: handle error code on RC query
drivers/media/usb/dvb-usb/af9005.c | 211 +++++++++++++++-------------
drivers/media/usb/dvb-usb/cinergyT2-core.c | 52 ++++---
drivers/media/usb/dvb-usb/cinergyT2-fe.c | 91 ++++--------
drivers/media/usb/dvb-usb/cxusb.c | 20 +--
drivers/media/usb/dvb-usb/cxusb.h | 5 +
drivers/media/usb/dvb-usb/dib0700_core.c | 31 +++-
drivers/media/usb/dvb-usb/dib0700_devices.c | 25 ++--
drivers/media/usb/dvb-usb/dibusb-common.c | 112 +++++++++++----
drivers/media/usb/dvb-usb/dibusb.h | 5 +
drivers/media/usb/dvb-usb/digitv.c | 26 ++--
drivers/media/usb/dvb-usb/digitv.h | 3 +
drivers/media/usb/dvb-usb/dtt200u-fe.c | 90 ++++++++----
drivers/media/usb/dvb-usb/dtt200u.c | 80 +++++++----
drivers/media/usb/dvb-usb/dtv5100.c | 10 +-
drivers/media/usb/dvb-usb/dvb-usb.h | 6 +-
drivers/media/usb/dvb-usb/dw2102.c | 2 +-
drivers/media/usb/dvb-usb/gp8psk.c | 25 +++-
drivers/media/usb/dvb-usb/nova-t-usb2.c | 25 +++-
drivers/media/usb/dvb-usb/pctv452e.c | 118 ++++++++--------
drivers/media/usb/dvb-usb/technisat-usb2.c | 16 ++-
20 files changed, 577 insertions(+), 376 deletions(-)
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