The concern is about the code on line 400. I'm not seeing where num_written could go below 0, in any case.
julia ---------- Forwarded message ---------- Date: Sun, 18 Feb 2018 20:54:49 +0800 From: kbuild test robot <fengguang...@intel.com> To: kbu...@01.org Cc: Julia Lawall <julia.law...@lip6.fr> Subject: Re: [PATCH v3] rtc: isl12026: Add driver. CC: kbuild-...@01.org In-Reply-To: <20180215195437.29207-1-david.da...@cavium.com> References: <20180215195437.29207-1-david.da...@cavium.com> TO: David Daney <david.da...@cavium.com> CC: Alessandro Zummo <a.zu...@towertech.it>, Alexandre Belloni <alexandre.bell...@free-electrons.com>, Rob Herring <robh...@kernel.org>, Mark Rutland <mark.rutl...@arm.com>, linux-...@vger.kernel.org, devicet...@vger.kernel.org, linux-kernel@vger.kernel.org, David Daney <david.da...@cavium.com> CC: linux-kernel@vger.kernel.org, David Daney <david.da...@cavium.com> Hi David, I love your patch! Perhaps something to improve: [auto build test WARNING on abelloni/rtc-next] [also build test WARNING on v4.16-rc1 next-20180216] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] url: https://github.com/0day-ci/linux/commits/David-Daney/rtc-isl12026-Add-driver/20180218-072946 base: https://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux.git rtc-next :::::: branch date: 13 hours ago :::::: commit date: 13 hours ago >> drivers/rtc/rtc-isl12026.c:400:8-19: WARNING: Unsigned expression compared >> with zero: num_written >= 0 # https://github.com/0day-ci/linux/commit/a0c9ca2899586c1317ebcb2ba5d31edde176a58a git remote add linux-review https://github.com/0day-ci/linux git remote update linux-review git checkout a0c9ca2899586c1317ebcb2ba5d31edde176a58a vim +400 drivers/rtc/rtc-isl12026.c a0c9ca28 David Daney 2018-02-15 347 a0c9ca28 David Daney 2018-02-15 348 static int isl12026_nvm_write(void *p, unsigned int offset, a0c9ca28 David Daney 2018-02-15 349 void *val, size_t bytes) a0c9ca28 David Daney 2018-02-15 350 { a0c9ca28 David Daney 2018-02-15 351 struct isl12026 *priv = p; a0c9ca28 David Daney 2018-02-15 352 int ret = -EIO; a0c9ca28 David Daney 2018-02-15 353 u8 *v = val; a0c9ca28 David Daney 2018-02-15 354 size_t chunk_size, num_written; a0c9ca28 David Daney 2018-02-15 355 u8 payload[ISL12026_PAGESIZE + 2]; /* page + 2 address bytes */ a0c9ca28 David Daney 2018-02-15 356 struct i2c_msg msgs[] = { a0c9ca28 David Daney 2018-02-15 357 { a0c9ca28 David Daney 2018-02-15 358 .addr = priv->nvm_client->addr, a0c9ca28 David Daney 2018-02-15 359 .flags = 0, a0c9ca28 David Daney 2018-02-15 360 .buf = payload a0c9ca28 David Daney 2018-02-15 361 } a0c9ca28 David Daney 2018-02-15 362 }; a0c9ca28 David Daney 2018-02-15 363 a0c9ca28 David Daney 2018-02-15 364 if (offset >= priv->nvm_cfg.size) a0c9ca28 David Daney 2018-02-15 365 return 0; /* End-of-file */ a0c9ca28 David Daney 2018-02-15 366 if (offset + bytes > priv->nvm_cfg.size) a0c9ca28 David Daney 2018-02-15 367 bytes = priv->nvm_cfg.size - offset; a0c9ca28 David Daney 2018-02-15 368 a0c9ca28 David Daney 2018-02-15 369 mutex_lock(&priv->lock); a0c9ca28 David Daney 2018-02-15 370 a0c9ca28 David Daney 2018-02-15 371 num_written = 0; a0c9ca28 David Daney 2018-02-15 372 while (bytes) { a0c9ca28 David Daney 2018-02-15 373 chunk_size = round_down(offset, ISL12026_PAGESIZE) + a0c9ca28 David Daney 2018-02-15 374 ISL12026_PAGESIZE - offset; a0c9ca28 David Daney 2018-02-15 375 chunk_size = min(bytes, chunk_size); a0c9ca28 David Daney 2018-02-15 376 /* a0c9ca28 David Daney 2018-02-15 377 * 2 bytes of address, most significant first, followed a0c9ca28 David Daney 2018-02-15 378 * by page data bytes a0c9ca28 David Daney 2018-02-15 379 */ a0c9ca28 David Daney 2018-02-15 380 memcpy(payload + 2, v + num_written, chunk_size); a0c9ca28 David Daney 2018-02-15 381 payload[0] = offset >> 8; a0c9ca28 David Daney 2018-02-15 382 payload[1] = offset; a0c9ca28 David Daney 2018-02-15 383 msgs[0].len = chunk_size + 2; a0c9ca28 David Daney 2018-02-15 384 ret = i2c_transfer(priv->nvm_client->adapter, a0c9ca28 David Daney 2018-02-15 385 msgs, ARRAY_SIZE(msgs)); a0c9ca28 David Daney 2018-02-15 386 if (ret != ARRAY_SIZE(msgs)) { a0c9ca28 David Daney 2018-02-15 387 dev_err(priv->nvm_cfg.dev, a0c9ca28 David Daney 2018-02-15 388 "nvmem write error, ret=%d\n", ret); a0c9ca28 David Daney 2018-02-15 389 ret = ret < 0 ? ret : -EIO; a0c9ca28 David Daney 2018-02-15 390 break; a0c9ca28 David Daney 2018-02-15 391 } a0c9ca28 David Daney 2018-02-15 392 bytes -= chunk_size; a0c9ca28 David Daney 2018-02-15 393 offset += chunk_size; a0c9ca28 David Daney 2018-02-15 394 num_written += chunk_size; a0c9ca28 David Daney 2018-02-15 395 msleep(ISL12026_NVMEM_WRITE_TIME); a0c9ca28 David Daney 2018-02-15 396 } a0c9ca28 David Daney 2018-02-15 397 a0c9ca28 David Daney 2018-02-15 398 mutex_unlock(&priv->lock); a0c9ca28 David Daney 2018-02-15 399 a0c9ca28 David Daney 2018-02-15 @400 return num_written >= 0 ? num_written : ret; a0c9ca28 David Daney 2018-02-15 401 } a0c9ca28 David Daney 2018-02-15 402 --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation
