Hi Simon, On Mon, Oct 1, 2018 at 3:52 PM Simon Horman <horms@xxxxxxxxxxxx> wrote: > On Mon, Oct 01, 2018 at 12:08:38PM +0200, Geert Uytterhoeven wrote: > > On Tue, Sep 18, 2018 at 10:51 AM Simon Horman <horms@xxxxxxxxxxxx> wrote: > > > This is intended as a submission to LTSI-4.14. It is the backport > > > of a fixes for safe DMA buffer handling for the SH-Mobile I2C driver > > > and I2C code. All patches are present in v4.19-rc3. > > > > > > This pull-request is based on > > > "[GIT PULL LTSI-4.14] LTSI-v4.14 Backport or I2C R-Car Fix" > > > tagged as backport/v4.14.61/snapshot-to-v4.18+fixes-flattened, > > > which I have already sent a pull-request for. > > > > > > There are 10 patches. > > > > > > I have performed build testing of this backports on a wide range of > > > defconfigs and I am not aware of any regressions over v4.14.40 (the > > > baseline chosen when this work began). > > > > > > The following changes since commit 4d4605e5c137ed9a53582e573118cbc16b82cbf1: > > > > > > i2c: rcar: implement STOP and REP_START according to docs (2018-08-28 13:35:06 +0200) > > > > > > are available in the git repository at: > > > > > > https://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas-backport.git backport/v4.14.61/snapshot-to-v4.18+fixes-v2-flattened > > > > > > for you to fetch changes up to 720043a4efbb3356db116d084c7b877ad41ee51a: > > > > > > i2c: sh_mobile: fix leak when using DMA bounce buffer (2018-09-17 15:54:30 +0200) > > > > > > ---------------------------------------------------------------- > > > Second Round of LTSI-v4.14 Backports of I2C R-Car Fixes > > > > > > Base: > > > * v4.14.61 > > > * Backports of components for Renesas SoCs to v4.18 > > > * First round of Backports of I2C R-Car Fixes > > > > > > Backport of post-v4.18 fix for i2c-shmobile and I2C core > > > The focus of these fixes is to make DMA buffer handling safe > > > > > > ---------------------------------------------------------------- > > > Peter Rosin (1): > > > i2c: smbus: kill memory leak on emulated and failed DMA SMBus xfers > > > > > > Wenwen Wang (1): > > > i2c: core: smbus: fix a potential missing-check bug > > > > > > Wolfram Sang (8): > > > i2c: dev: mark RDWR buffers as DMA_SAFE > > > i2c: refactor i2c_master_{send_recv} > > > i2c: add i2c_master_{send|recv}_dmasafe > > > i2c: smbus: use DMA safe buffers for emulated SMBus transactions > > > i2c: add docs to clarify DMA handling > > > i2c: refactor function to release a DMA safe buffer > > > i2c: sh_mobile: define start_ch() void as it only returns 0 anyhow > > > > Somehow I missed that the above introduces a (rightful) compiler warning: > > > > drivers/i2c/busses/i2c-sh_mobile.c: In function ‘start_ch’: > > drivers/i2c/busses/i2c-sh_mobile.c:616:10: warning: ‘return’ with > > a value, in function returning void > > return -EOPNOTSUPP; > > ^ > > drivers/i2c/busses/i2c-sh_mobile.c:611:13: note: declared here > > static void start_ch(struct sh_mobile_i2c_data *pd, struct > > i2c_msg *usr_msg, > > ^~~~~~~~ > > > > as it depends on commit 7957c2e276ee73e6 ("i2c: sh_mobile: use core to > > detect 'no zero length read' quirk"), which was not backported. > > > > I think the easiest solution is to just drop "i2c: sh_mobile: define > > start_ch() void as it only returns 0 anyhow", as it was meant not to > > introduce any behavioral changes, and nothing depends on it. > > > > Do you agree? > > Thanks! > > Likewise, thanks for pointing this out. > > Your proposed solution looks good to me. > Have you tested it? More or less, the error case is not easily triggered, and the code should behave as before. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
