linux-stable.git/drivers/nvmem, branch linux-4.17.y

nvmem: Don't let a NULL cell_id for nvmem_cell_get() crash us

2018-08-24T11:07:02+00:00

[ Upstream commit 87ed1405ef09d29a14df43295f7b6a93b63bfe6e ]

In commit ca04d9d3e1b1 ("phy: qcom-qusb2: New driver for QUSB2 PHY on
Qcom chips") you can see a call like:

  devm_nvmem_cell_get(dev, NULL);

Note that the cell ID passed to the function is NULL.  This is because
the qcom-qusb2 driver is expected to work only on systems where the
PHY node is hooked up via device-tree and is nameless.

This works OK for the most part.  The first thing nvmem_cell_get()
does is to call of_nvmem_cell_get() and there it's documented that a
NULL name is fine.  The problem happens when the call to
of_nvmem_cell_get() returns -EINVAL.  In such a case we'll fall back
to nvmem_cell_get_from_list() and eventually might (if nvmem_cells
isn't an empty list) crash with something that looks like:

 strcmp
 nvmem_find_cell
 __nvmem_device_get
 nvmem_cell_get_from_list
 nvmem_cell_get
 devm_nvmem_cell_get
 qusb2_phy_probe

There are several different ways we could fix this problem:

One could argue that perhaps the qcom-qusb2 driver should be changed
to use of_nvmem_cell_get() which is allowed to have a NULL name.  In
that case, we'd need to add a patche to introduce
devm_of_nvmem_cell_get() since the qcom-qusb2 driver is using devm
managed resources.

One could also argue that perhaps we could just add a name to
qcom-qusb2.  That would be OK but I believe it effectively changes the
device tree bindings, so maybe it's a no-go.

In this patch I have chosen to fix the problem by simply not crashing
when a NULL cell_id is passed to nvmem_cell_get().

NOTE: that for the qcom-qusb2 driver the "nvmem-cells" property is
defined to be optional and thus it's expected to be a common case that
we would hit this crash and this is more than just a theoretical fix.

Fixes: ca04d9d3e1b1 ("phy: qcom-qusb2: New driver for QUSB2 PHY on Qcom chips")
Signed-off-by: Douglas Anderson 
Signed-off-by: Srinivas Kandagatla 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

nvmem: properly handle returned value nvmem_reg_read

2018-08-03T05:47:52+00:00

[ Upstream commit 50808bfcc14b854775a9f1d0abe3dac2babcf5c3 ]

Function nvmem_reg_read can return a non zero value indicating an error.
This returned value must be read and error propagated to
nvmem_cell_prepare_write_buffer. Silence the following gcc warning (W=1):

drivers/nvmem/core.c:1093:9: warning: variable 'rc' set but
 not used [-Wunused-but-set-variable]

Signed-off-by: Mathieu Malaterre 
Signed-off-by: Srinivas Kandagatla 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'char-misc-4.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2018-04-05T03:07:20+00:00

Pull char/misc updates from Greg KH:
 "Here is the big set of char/misc driver patches for 4.17-rc1.

  There are a lot of little things in here, nothing huge, but all
  important to the different hardware types involved:

   -  thunderbolt driver updates

   -  parport updates (people still care...)

   -  nvmem driver updates

   -  mei updates (as always)

   -  hwtracing driver updates

   -  hyperv driver updates

   -  extcon driver updates

   -  ... and a handful of even smaller driver subsystem and individual
      driver updates

  All of these have been in linux-next with no reported issues"

* tag 'char-misc-4.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (149 commits)
  hwtracing: Add HW tracing support menu
  intel_th: Add ACPI glue layer
  intel_th: Allow forcing host mode through drvdata
  intel_th: Pick up irq number from resources
  intel_th: Don't touch switch routing in host mode
  intel_th: Use correct method of finding hub
  intel_th: Add SPDX GPL-2.0 header to replace GPLv2 boilerplate
  stm class: Make dummy's master/channel ranges configurable
  stm class: Add SPDX GPL-2.0 header to replace GPLv2 boilerplate
  MAINTAINERS: Bestow upon myself the care for drivers/hwtracing
  hv: add SPDX license id to Kconfig
  hv: add SPDX license to trace
  Drivers: hv: vmbus: do not mark HV_PCIE as perf_device
  Drivers: hv: vmbus: respect what we get from hv_get_synint_state()
  /dev/mem: Avoid overwriting "err" in read_mem()
  eeprom: at24: use SPDX identifier instead of GPL boiler-plate
  eeprom: at24: simplify the i2c functionality checking
  eeprom: at24: fix a line break
  eeprom: at24: tweak newlines
  eeprom: at24: refactor at24_probe()
  ...

nvmem: disallow modular CONFIG_NVMEM

2018-04-04T15:47:50+00:00

The new of_get_nvmem_mac_address() helper function causes a link error
with CONFIG_NVMEM=m:

drivers/of/of_net.o: In function `of_get_nvmem_mac_address':
of_net.c:(.text+0x168): undefined reference to `of_nvmem_cell_get'
of_net.c:(.text+0x19c): undefined reference to `nvmem_cell_read'
of_net.c:(.text+0x1a8): undefined reference to `nvmem_cell_put'

I could not come up with a good solution for this, as the code is always
built-in. Using an #if IS_REACHABLE() check around it would solve the
link time issue but then stop it from working in that configuration.
Making of_nvmem_cell_get() an inline function could also solve that, but
seems a bit ugly since it's somewhat larger than most inline functions,
and it would just bring that problem into the callers.  Splitting the
function into a separate file might be an alternative.

This uses the big hammer by making CONFIG_NVMEM itself a 'bool' symbol,
which avoids the problem entirely but makes the vmlinux larger for anyone
that might use NVMEM support but doesn't need it built-in otherwise.

Fixes: 9217e566bdee ("of_net: Implement of_get_nvmem_mac_address helper")
Cc: Mike Looijmans 
Cc: Florian Fainelli 
Cc: Andrew Lunn 
Cc: David S. Miller 
Cc: netdev@vger.kernel.org
Signed-off-by: Arnd Bergmann 
Acked-by: Mike Looijmans
Signed-off-by: David S. Miller

nvmem: imx-ocotp: remove unused dead code

2018-03-14T18:28:15+00:00

remove unused dead code

Cc: Srinivas Kandagatla 
Cc: Shawn Guo 
Signed-off-by: Dong Aisheng 
Acked-by: Shawn Guo 
Signed-off-by: Srinivas Kandagatla 
Signed-off-by: Greg Kroah-Hartman

nvmem: sunxi-sid: fix H3 SID controller support

2018-03-14T18:28:15+00:00

It seems that doing some operation will make the value pre-read on H3
SID controller wrong again, so all operation should be performed by
register.

Change the SID reading to use register only.

Signed-off-by: Icenowy Zheng 
Signed-off-by: Srinivas Kandagatla 
Signed-off-by: Greg Kroah-Hartman

nvmem: add i.MX7 support to snvs-lpgpr

2018-03-14T18:28:14+00:00

The i.MX7 family has similar SNVS hardware so make the snvs-lpgpr
support it along with the i.MX6 family. The register interface is the
same except for the number and offset of the general purpose registers.

Signed-off-by: Andrey Yurovsky 
Reviewed-by: Oleksij Rempel 
Signed-off-by: Srinivas Kandagatla 
Signed-off-by: Greg Kroah-Hartman

nvmem: bcm-ocotp: Do not use "&pdev->dev" explicitly

2018-03-14T18:28:14+00:00

There's "dev" variable for this already. Use it.

Cc: Srinivas Kandagatla 
Cc: Heiko Stuebner 
Cc: Masahiro Yamada 
Cc: Carlo Caione 
Cc: Kevin Hilman 
Cc: Matthias Brugger 
Cc: cphealy@gmail.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-mediatek@lists.infradead.org
Cc: linux-rockchip@lists.infradead.org
Cc: linux-amlogic@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Andrey Smirnov 
Signed-off-by: Srinivas Kandagatla 
Signed-off-by: Greg Kroah-Hartman

nvmem: imx-iim: Do not use "&pdev->dev" explicitly

2018-03-14T18:28:14+00:00

There's already "dev" variable for that. Use it.

Cc: Srinivas Kandagatla 
Cc: Heiko Stuebner 
Cc: Masahiro Yamada 
Cc: Carlo Caione 
Cc: Kevin Hilman 
Cc: Matthias Brugger 
Cc: cphealy@gmail.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-mediatek@lists.infradead.org
Cc: linux-rockchip@lists.infradead.org
Cc: linux-amlogic@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Andrey Smirnov 
Signed-off-by: Srinivas Kandagatla 
Signed-off-by: Greg Kroah-Hartman

nvmem: rockchip-efuse: Do not use "&pdev->dev" explicitly

2018-03-14T18:28:14+00:00

There's "dev" variable for this already. Use it.

Cc: Srinivas Kandagatla 
Cc: Heiko Stuebner 
Cc: Masahiro Yamada 
Cc: Carlo Caione 
Cc: Kevin Hilman 
Cc: Matthias Brugger 
Cc: cphealy@gmail.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-mediatek@lists.infradead.org
Cc: linux-rockchip@lists.infradead.org
Cc: linux-amlogic@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Andrey Smirnov 
Signed-off-by: Srinivas Kandagatla 
Signed-off-by: Greg Kroah-Hartman