5.4-stable review patch. If anyone has any objections, please let me know.
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From: Wentao Liang vulab@iscas.ac.cn
commit b9644fbfbcab13da7f8b37bef7c51e5b8407d031 upstream.
The stmpe_reg_read function can fail, but its return value is not checked in stmpe_gpio_irq_sync_unlock. This can lead to silent failures and incorrect behavior if the hardware access fails.
This patch adds checks for the return value of stmpe_reg_read. If the function fails, an error message is logged and the function returns early to avoid further issues.
Fixes: b888fb6f2a27 ("gpio: stmpe: i2c transfer are forbiden in atomic context") Cc: stable@vger.kernel.org # 4.16+ Signed-off-by: Wentao Liang vulab@iscas.ac.cn Link: https://lore.kernel.org/r/20250212021849.275-1-vulab@iscas.ac.cn Signed-off-by: Bartosz Golaszewski bartosz.golaszewski@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpio/gpio-stmpe.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)
--- a/drivers/gpio/gpio-stmpe.c +++ b/drivers/gpio/gpio-stmpe.c @@ -188,7 +188,7 @@ static void stmpe_gpio_irq_sync_unlock(s [REG_IE][CSB] = STMPE_IDX_IEGPIOR_CSB, [REG_IE][MSB] = STMPE_IDX_IEGPIOR_MSB, }; - int i, j; + int ret, i, j;
/* * STMPE1600: to be able to get IRQ from pins, @@ -196,8 +196,16 @@ static void stmpe_gpio_irq_sync_unlock(s * GPSR or GPCR registers */ if (stmpe->partnum == STMPE1600) { - stmpe_reg_read(stmpe, stmpe->regs[STMPE_IDX_GPMR_LSB]); - stmpe_reg_read(stmpe, stmpe->regs[STMPE_IDX_GPMR_CSB]); + ret = stmpe_reg_read(stmpe, stmpe->regs[STMPE_IDX_GPMR_LSB]); + if (ret < 0) { + dev_err(stmpe->dev, "Failed to read GPMR_LSB: %d\n", ret); + goto err; + } + ret = stmpe_reg_read(stmpe, stmpe->regs[STMPE_IDX_GPMR_CSB]); + if (ret < 0) { + dev_err(stmpe->dev, "Failed to read GPMR_CSB: %d\n", ret); + goto err; + } }
for (i = 0; i < CACHE_NR_REGS; i++) { @@ -219,6 +227,7 @@ static void stmpe_gpio_irq_sync_unlock(s } }
+err: mutex_unlock(&stmpe_gpio->irq_lock); }