The qup_i2c_xfer_v2() calls the qup_i2c_change_state() but does not check its return value. A proper implementation can be found in qup_i2c_xfer().
Add error handling for qup_i2c_change_state(). If the function fails, return the error code.
Fixes: 7545c7dba169 ("i2c: qup: reorganization of driver code to remove polling for qup v2") Cc: stable@vger.kernel.org # v4.17 Signed-off-by: Wentao Liang vulab@iscas.ac.cn --- drivers/i2c/busses/i2c-qup.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c index da20b4487c9a..2477f570fe86 100644 --- a/drivers/i2c/busses/i2c-qup.c +++ b/drivers/i2c/busses/i2c-qup.c @@ -1538,7 +1538,7 @@ static int qup_i2c_xfer_v2(struct i2c_adapter *adap, int num) { struct qup_i2c_dev *qup = i2c_get_adapdata(adap); - int ret, idx = 0; + int ret, err, idx = 0;
qup->bus_err = 0; qup->qup_err = 0; @@ -1588,7 +1588,9 @@ static int qup_i2c_xfer_v2(struct i2c_adapter *adap, ret = qup_i2c_bus_active(qup, ONE_BYTE);
if (!ret) - qup_i2c_change_state(qup, QUP_RESET_STATE); + err = qup_i2c_change_state(qup, QUP_RESET_STATE); + if (err) + return err;
if (ret == 0) ret = num;
Hi Wentao,
On Mon, May 19, 2025 at 10:19:18PM +0800, Wentao Liang wrote:
The qup_i2c_xfer_v2() calls the qup_i2c_change_state() but does not check its return value. A proper implementation can be found in qup_i2c_xfer().
Add error handling for qup_i2c_change_state(). If the function fails, return the error code.
Fixes: 7545c7dba169 ("i2c: qup: reorganization of driver code to remove polling for qup v2") Cc: stable@vger.kernel.org # v4.17
no need to Cc stable here, it's not such a big issue.
Signed-off-by: Wentao Liang vulab@iscas.ac.cn
drivers/i2c/busses/i2c-qup.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c index da20b4487c9a..2477f570fe86 100644 --- a/drivers/i2c/busses/i2c-qup.c +++ b/drivers/i2c/busses/i2c-qup.c @@ -1538,7 +1538,7 @@ static int qup_i2c_xfer_v2(struct i2c_adapter *adap, int num) { struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
- int ret, idx = 0;
- int ret, err, idx = 0;
qup->bus_err = 0; qup->qup_err = 0; @@ -1588,7 +1588,9 @@ static int qup_i2c_xfer_v2(struct i2c_adapter *adap, ret = qup_i2c_bus_active(qup, ONE_BYTE); if (!ret)
qup_i2c_change_state(qup, QUP_RESET_STATE);
err = qup_i2c_change_state(qup, QUP_RESET_STATE);
This check was removed on purpose, not by accident in the commit you pointed out in the Fixes tag. On the other hand I agree that this needs to be checked, perhaps restoring the original code:
if (!ret) ret = qup_i2c_change_state(qup, QUP_RESET_STATE);
if (ret == 0) ret = num;
What is exactly that you are trying to fix here? What is the error you have faced?
Thanks, Andi
- if (err)
return err;if (ret == 0) ret = num;
PS: your code can be refactored in a way that we don't need this extra variable. E.g., something like this:
if (!ret) ret = qup_i2c_bus_active(qup, ONE_BYTE);
if (!ret) { ret = qup_i2c_change_state(qup, QUP_RESET_STATE); if (ret) return ret; ret = num; }
Looks the same, no? But I think the original version should work better.
On 5/19/2025 7:49 PM, Wentao Liang wrote:
The qup_i2c_xfer_v2() calls the qup_i2c_change_state() but does not check its return value. A proper implementation can be found in qup_i2c_xfer().
Add error handling for qup_i2c_change_state(). If the function fails, return the error code.
Fixes: 7545c7dba169 ("i2c: qup: reorganization of driver code to remove polling for qup v2") Cc: stable@vger.kernel.org # v4.17 Signed-off-by: Wentao Liang vulab@iscas.ac.cn
drivers/i2c/busses/i2c-qup.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c index da20b4487c9a..2477f570fe86 100644 --- a/drivers/i2c/busses/i2c-qup.c +++ b/drivers/i2c/busses/i2c-qup.c @@ -1538,7 +1538,7 @@ static int qup_i2c_xfer_v2(struct i2c_adapter *adap, int num) { struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
- int ret, idx = 0;
- int ret, err, idx = 0;
qup->bus_err = 0; qup->qup_err = 0; @@ -1588,7 +1588,9 @@ static int qup_i2c_xfer_v2(struct i2c_adapter *adap, ret = qup_i2c_bus_active(qup, ONE_BYTE); if (!ret)
qup_i2c_change_state(qup, QUP_RESET_STATE);
err = qup_i2c_change_state(qup, QUP_RESET_STATE);- if (err)
return err;
Is there an error seen around this ? Expecting this to work as is. After an error, what next ? Just return back to framework ?
if (ret == 0) ret = num;
Hi Mukesh,
...
@@ -1588,7 +1588,9 @@ static int qup_i2c_xfer_v2(struct i2c_adapter *adap, ret = qup_i2c_bus_active(qup, ONE_BYTE); if (!ret)
qup_i2c_change_state(qup, QUP_RESET_STATE);
err = qup_i2c_change_state(qup, QUP_RESET_STATE);- if (err)
return err;Is there an error seen around this ? Expecting this to work as is. After an error, what next ? Just return back to framework ?
thanks for chiming in. qup_i2c_change_state() can fail, why shouldn't we consider the possibility to fail?
Thanks, Andi
Hi Wentao,
kernel test robot noticed the following build warnings:
[auto build test WARNING on andi-shyti/i2c/i2c-host] [also build test WARNING on linus/master v6.15-rc7 next-20250516] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Wentao-Liang/i2c-qup-Add-erro... base: https://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux.git i2c/i2c-host patch link: https://lore.kernel.org/r/20250519141918.2522-1-vulab%40iscas.ac.cn patch subject: [PATCH] i2c: qup: Add error handling in qup_i2c_xfer_v2() config: hexagon-randconfig-001-20250521 (https://download.01.org/0day-ci/archive/20250521/202505210438.G4nfkpQ2-lkp@i...) compiler: clang version 20.1.2 (https://github.com/llvm/llvm-project 58df0ef89dd64126512e4ee27b4ac3fd8ddf6247) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250521/202505210438.G4nfkpQ2-lkp@i...)
If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot lkp@intel.com | Closes: https://lore.kernel.org/oe-kbuild-all/202505210438.G4nfkpQ2-lkp@intel.com/
All warnings (new ones prefixed by >>):
drivers/i2c/busses/i2c-qup.c:1619:6: warning: variable 'err' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
1619 | if (!ret) | ^~~~ drivers/i2c/busses/i2c-qup.c:1621:6: note: uninitialized use occurs here 1621 | if (err) | ^~~ drivers/i2c/busses/i2c-qup.c:1619:2: note: remove the 'if' if its condition is always true 1619 | if (!ret) | ^~~~~~~~~ 1620 | err = qup_i2c_change_state(qup, QUP_RESET_STATE); drivers/i2c/busses/i2c-qup.c:1570:14: note: initialize the variable 'err' to silence this warning 1570 | int ret, err, idx = 0; | ^ | = 0 1 warning generated.
vim +1619 drivers/i2c/busses/i2c-qup.c
7545c7dba169c4 Abhishek Sahu 2018-03-12 1564 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1565 static int qup_i2c_xfer_v2(struct i2c_adapter *adap, 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1566 struct i2c_msg msgs[], 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1567 int num) 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1568 { 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1569 struct qup_i2c_dev *qup = i2c_get_adapdata(adap); 61f647e9d36d67 Wentao Liang 2025-05-19 1570 int ret, err, idx = 0; 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1571 fbf9921f8b35d9 Sricharan Ramabadhran 2016-06-10 1572 qup->bus_err = 0; fbf9921f8b35d9 Sricharan Ramabadhran 2016-06-10 1573 qup->qup_err = 0; fbf9921f8b35d9 Sricharan Ramabadhran 2016-06-10 1574 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1575 ret = pm_runtime_get_sync(qup->dev); 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1576 if (ret < 0) 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1577 goto out; 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1578 7545c7dba169c4 Abhishek Sahu 2018-03-12 1579 ret = qup_i2c_determine_mode_v2(qup, msgs, num); 7545c7dba169c4 Abhishek Sahu 2018-03-12 1580 if (ret) 7545c7dba169c4 Abhishek Sahu 2018-03-12 1581 goto out; 7545c7dba169c4 Abhishek Sahu 2018-03-12 1582 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1583 writel(1, qup->base + QUP_SW_RESET); 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1584 ret = qup_i2c_poll_state(qup, QUP_RESET_STATE); 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1585 if (ret) 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1586 goto out; 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1587 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1588 /* Configure QUP as I2C mini core */ 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1589 writel(I2C_MINI_CORE | I2C_N_VAL_V2, qup->base + QUP_CONFIG); 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1590 writel(QUP_V2_TAGS_EN, qup->base + QUP_I2C_MASTER_GEN); 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1591 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1592 if (qup_i2c_poll_state_i2c_master(qup)) { 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1593 ret = -EIO; 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1594 goto out; 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1595 } 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1596 eb422b539c1f39 Abhishek Sahu 2018-03-12 1597 if (qup->use_dma) { 7545c7dba169c4 Abhishek Sahu 2018-03-12 1598 reinit_completion(&qup->xfer); 7545c7dba169c4 Abhishek Sahu 2018-03-12 1599 ret = qup_i2c_bam_xfer(adap, &msgs[0], num); eb422b539c1f39 Abhishek Sahu 2018-03-12 1600 qup->use_dma = false; 9cedf3b2f09946 Sricharan Ramabadhran 2016-02-22 1601 } else { 7545c7dba169c4 Abhishek Sahu 2018-03-12 1602 qup_i2c_conf_mode_v2(qup); 7545c7dba169c4 Abhishek Sahu 2018-03-12 1603 7545c7dba169c4 Abhishek Sahu 2018-03-12 1604 for (idx = 0; idx < num; idx++) { 7545c7dba169c4 Abhishek Sahu 2018-03-12 1605 qup->msg = &msgs[idx]; 7545c7dba169c4 Abhishek Sahu 2018-03-12 1606 qup->is_last = idx == (num - 1); 7545c7dba169c4 Abhishek Sahu 2018-03-12 1607 7545c7dba169c4 Abhishek Sahu 2018-03-12 1608 ret = qup_i2c_xfer_v2_msg(qup, idx, 7545c7dba169c4 Abhishek Sahu 2018-03-12 1609 !!(msgs[idx].flags & I2C_M_RD)); 7545c7dba169c4 Abhishek Sahu 2018-03-12 1610 if (ret) 7545c7dba169c4 Abhishek Sahu 2018-03-12 1611 break; 7545c7dba169c4 Abhishek Sahu 2018-03-12 1612 } 7545c7dba169c4 Abhishek Sahu 2018-03-12 1613 qup->msg = NULL; 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1614 } 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1615 f74187932d30e4 Sricharan Ramabadhran 2016-01-19 1616 if (!ret) 7545c7dba169c4 Abhishek Sahu 2018-03-12 1617 ret = qup_i2c_bus_active(qup, ONE_BYTE); 7545c7dba169c4 Abhishek Sahu 2018-03-12 1618 7545c7dba169c4 Abhishek Sahu 2018-03-12 @1619 if (!ret) 61f647e9d36d67 Wentao Liang 2025-05-19 1620 err = qup_i2c_change_state(qup, QUP_RESET_STATE); 61f647e9d36d67 Wentao Liang 2025-05-19 1621 if (err) 61f647e9d36d67 Wentao Liang 2025-05-19 1622 return err; f74187932d30e4 Sricharan Ramabadhran 2016-01-19 1623 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1624 if (ret == 0) 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1625 ret = num; 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1626 out: 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1627 pm_runtime_mark_last_busy(qup->dev); 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1628 pm_runtime_put_autosuspend(qup->dev); 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1629 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1630 return ret; 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1631 } 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1632
Hi Wentao,
kernel test robot noticed the following build warnings:
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Wentao-Liang/i2c-qup-Add-erro... base: https://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux.git i2c/i2c-host patch link: https://lore.kernel.org/r/20250519141918.2522-1-vulab%40iscas.ac.cn patch subject: [PATCH] i2c: qup: Add error handling in qup_i2c_xfer_v2() config: powerpc64-randconfig-r071-20250522 (https://download.01.org/0day-ci/archive/20250522/202505221445.quJVHqSz-lkp@i...) compiler: clang version 21.0.0git (https://github.com/llvm/llvm-project f819f46284f2a79790038e1f6649172789734ae8)
If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot lkp@intel.com | Reported-by: Dan Carpenter dan.carpenter@linaro.org | Closes: https://lore.kernel.org/r/202505221445.quJVHqSz-lkp@intel.com/
smatch warnings: drivers/i2c/busses/i2c-qup.c:1621 qup_i2c_xfer_v2() error: uninitialized symbol 'err'.
vim +/err +1621 drivers/i2c/busses/i2c-qup.c
191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1565 static int qup_i2c_xfer_v2(struct i2c_adapter *adap, 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1566 struct i2c_msg msgs[], 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1567 int num) 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1568 { 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1569 struct qup_i2c_dev *qup = i2c_get_adapdata(adap); 61f647e9d36d67 Wentao Liang 2025-05-19 1570 int ret, err, idx = 0; 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1571 fbf9921f8b35d9 Sricharan Ramabadhran 2016-06-10 1572 qup->bus_err = 0; fbf9921f8b35d9 Sricharan Ramabadhran 2016-06-10 1573 qup->qup_err = 0; fbf9921f8b35d9 Sricharan Ramabadhran 2016-06-10 1574 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1575 ret = pm_runtime_get_sync(qup->dev); 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1576 if (ret < 0) 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1577 goto out; 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1578 7545c7dba169c4 Abhishek Sahu 2018-03-12 1579 ret = qup_i2c_determine_mode_v2(qup, msgs, num); 7545c7dba169c4 Abhishek Sahu 2018-03-12 1580 if (ret) 7545c7dba169c4 Abhishek Sahu 2018-03-12 1581 goto out; 7545c7dba169c4 Abhishek Sahu 2018-03-12 1582 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1583 writel(1, qup->base + QUP_SW_RESET); 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1584 ret = qup_i2c_poll_state(qup, QUP_RESET_STATE); 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1585 if (ret) 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1586 goto out; 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1587 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1588 /* Configure QUP as I2C mini core */ 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1589 writel(I2C_MINI_CORE | I2C_N_VAL_V2, qup->base + QUP_CONFIG); 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1590 writel(QUP_V2_TAGS_EN, qup->base + QUP_I2C_MASTER_GEN); 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1591 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1592 if (qup_i2c_poll_state_i2c_master(qup)) { 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1593 ret = -EIO; 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1594 goto out; 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1595 } 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1596 eb422b539c1f39 Abhishek Sahu 2018-03-12 1597 if (qup->use_dma) { 7545c7dba169c4 Abhishek Sahu 2018-03-12 1598 reinit_completion(&qup->xfer); 7545c7dba169c4 Abhishek Sahu 2018-03-12 1599 ret = qup_i2c_bam_xfer(adap, &msgs[0], num); eb422b539c1f39 Abhishek Sahu 2018-03-12 1600 qup->use_dma = false; 9cedf3b2f09946 Sricharan Ramabadhran 2016-02-22 1601 } else { 7545c7dba169c4 Abhishek Sahu 2018-03-12 1602 qup_i2c_conf_mode_v2(qup); 7545c7dba169c4 Abhishek Sahu 2018-03-12 1603 7545c7dba169c4 Abhishek Sahu 2018-03-12 1604 for (idx = 0; idx < num; idx++) { 7545c7dba169c4 Abhishek Sahu 2018-03-12 1605 qup->msg = &msgs[idx]; 7545c7dba169c4 Abhishek Sahu 2018-03-12 1606 qup->is_last = idx == (num - 1); 7545c7dba169c4 Abhishek Sahu 2018-03-12 1607 7545c7dba169c4 Abhishek Sahu 2018-03-12 1608 ret = qup_i2c_xfer_v2_msg(qup, idx, 7545c7dba169c4 Abhishek Sahu 2018-03-12 1609 !!(msgs[idx].flags & I2C_M_RD)); 7545c7dba169c4 Abhishek Sahu 2018-03-12 1610 if (ret) 7545c7dba169c4 Abhishek Sahu 2018-03-12 1611 break; 7545c7dba169c4 Abhishek Sahu 2018-03-12 1612 } 7545c7dba169c4 Abhishek Sahu 2018-03-12 1613 qup->msg = NULL; 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1614 } 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1615 f74187932d30e4 Sricharan Ramabadhran 2016-01-19 1616 if (!ret) 7545c7dba169c4 Abhishek Sahu 2018-03-12 1617 ret = qup_i2c_bus_active(qup, ONE_BYTE); 7545c7dba169c4 Abhishek Sahu 2018-03-12 1618 7545c7dba169c4 Abhishek Sahu 2018-03-12 1619 if (!ret) 61f647e9d36d67 Wentao Liang 2025-05-19 1620 err = qup_i2c_change_state(qup, QUP_RESET_STATE);
if ret was already set then err isn't initialized.
61f647e9d36d67 Wentao Liang 2025-05-19 @1621 if (err) ^^^ Uninitialized. In production obviously the only sane choice is CONFIG_INIT_STACK_ALL_ZERO but I really encourage developers to set CONFIG_INIT_STACK_ALL_PATTERN=y so that we catch these sorts of bugs in testing.
61f647e9d36d67 Wentao Liang 2025-05-19 1622 return err; f74187932d30e4 Sricharan Ramabadhran 2016-01-19 1623 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1624 if (ret == 0) 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1625 ret = num; 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1626 out: 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1627 pm_runtime_mark_last_busy(qup->dev); 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1628 pm_runtime_put_autosuspend(qup->dev); 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1629 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1630 return ret; 191424bb6166f6 Sricharan Ramabadhran 2016-01-19 1631 }
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