On Thu, Jun 13, 2024 at 05:51:39PM +0100, Ben Walsh wrote: > > Thanks for fixing this! Unfortunately `in_range` returns -EINVAL if > length == 0 (see the definition of `fwk_ec_lpc_mec_in_range`). I'm sure > this broke something in my testing, but I can't find what it was now. Somewhere like [1] could accidentally get the -EINVAL. [1]: https://elixir.bootlin.com/linux/v6.9/source/drivers/platform/chrome/cros_ec_lpc.c#L232 > > My original suggestion was to add a test for "length == 0" before the > "in_range" test, then do the test as you have done. But we decided to > defer this to a later, separate patch. > > There's also a similar "in_range" test in `fwk_ec_lpc_mec_write_bytes`. > > We could: > > 1. Revert this and change the `data & EC_LPC_STATUS_BUSY_MASK` to > `res & EC_LPC_STATUS_BUSY_MASK`. This is the same logic as before the > negative error code change. > > or 2. Put in a check for length == 0. > > or 3. Change the logic in `fwk_ec_lpc_mec_in_range`. Although I'm not > sure what the correct answer is to "zero length is in range?" > > I prefer option 2. What do you think? How about drop the length check at [2]? [2]: https://elixir.bootlin.com/linux/v6.9/source/drivers/platform/chrome/cros_ec_lpc_mec.c#L44 > > Dan Carpenter <dan.carpenter@xxxxxxxxxx> writes: > > > We changed these functions to returning negative error codes, but this > > first error path was accidentally overlooked. It leads to a Smatch > > warning: > > > > drivers/platform/chrome/cros_ec_lpc.c:181 ec_response_timed_out() > > error: uninitialized symbol 'data'. > > > > Fix this by returning the error code instead of success. > > > > Fixes: 68dbac0a58ef ("platform/chrome: cros_ec_lpc: MEC access can return error code") > > Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> > > --- > > drivers/platform/chrome/cros_ec_lpc.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c > > index ebe9fb143840..f0470248b109 100644 > > --- a/drivers/platform/chrome/cros_ec_lpc.c > > +++ b/drivers/platform/chrome/cros_ec_lpc.c > > @@ -139,7 +139,7 @@ static int cros_ec_lpc_mec_read_bytes(unsigned int offset, unsigned int length, > > int in_range = cros_ec_lpc_mec_in_range(offset, length); > > > > if (in_range < 0) > > - return 0; > > + return in_range; > > > > return in_range ? > > cros_ec_lpc_io_bytes_mec(MEC_IO_READ, > > @@ -158,7 +158,7 @@ static int cros_ec_lpc_mec_write_bytes(unsigned int offset, unsigned int length, > > int in_range = cros_ec_lpc_mec_in_range(offset, length); > > > > if (in_range < 0) > > - return 0; > > + return in_range; > > > > return in_range ? > > cros_ec_lpc_io_bytes_mec(MEC_IO_WRITE, > > -- > > 2.43.0 >
