* [PATCH] memory: samsung: exynos5422-dmc: Do not ignore return code of regmap_read()
@ 2020-07-20 11:03 Krzysztof Kozlowski
2020-07-27 8:35 ` Lukasz Luba
0 siblings, 1 reply; 2+ messages in thread
From: Krzysztof Kozlowski @ 2020-07-20 11:03 UTC (permalink / raw)
To: Lukasz Luba, Kukjin Kim, Krzysztof Kozlowski, linux-pm,
linux-samsung-soc, linux-arm-kernel, linux-kernel
Check for regmap_read() return code before using the read value in
following write in exynos5_switch_timing_regs(). Pass reading error
code to the callers.
This does not introduce proper error handling for such failed reads (and
obviously regmap_write() error is still ignored) because the driver
ignored this in all places. Therefor it only fixes reported issue while
matching current driver coding style:
drivers/memory/samsung/exynos5422-dmc.c: In function 'exynos5_switch_timing_regs':
>> drivers/memory/samsung/exynos5422-dmc.c:216:6: warning: variable 'ret' set but not used [-Wunused-but-set-variable]
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
drivers/memory/samsung/exynos5422-dmc.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/drivers/memory/samsung/exynos5422-dmc.c b/drivers/memory/samsung/exynos5422-dmc.c
index 93e9c2429c0d..2c326998cb1c 100644
--- a/drivers/memory/samsung/exynos5422-dmc.c
+++ b/drivers/memory/samsung/exynos5422-dmc.c
@@ -270,12 +270,14 @@ static int find_target_freq_idx(struct exynos5_dmc *dmc,
* This function switches between these banks according to the
* currently used clock source.
*/
-static void exynos5_switch_timing_regs(struct exynos5_dmc *dmc, bool set)
+static int exynos5_switch_timing_regs(struct exynos5_dmc *dmc, bool set)
{
unsigned int reg;
int ret;
ret = regmap_read(dmc->clk_regmap, CDREX_LPDDR3PHY_CON3, ®);
+ if (ret)
+ return ret;
if (set)
reg |= EXYNOS5_TIMING_SET_SWI;
@@ -283,6 +285,8 @@ static void exynos5_switch_timing_regs(struct exynos5_dmc *dmc, bool set)
reg &= ~EXYNOS5_TIMING_SET_SWI;
regmap_write(dmc->clk_regmap, CDREX_LPDDR3PHY_CON3, reg);
+
+ return 0;
}
/**
@@ -516,7 +520,7 @@ exynos5_dmc_switch_to_bypass_configuration(struct exynos5_dmc *dmc,
/*
* Delays are long enough, so use them for the new coming clock.
*/
- exynos5_switch_timing_regs(dmc, USE_MX_MSPLL_TIMINGS);
+ ret = exynos5_switch_timing_regs(dmc, USE_MX_MSPLL_TIMINGS);
return ret;
}
@@ -577,7 +581,9 @@ exynos5_dmc_change_freq_and_volt(struct exynos5_dmc *dmc,
clk_set_rate(dmc->fout_bpll, target_rate);
- exynos5_switch_timing_regs(dmc, USE_BPLL_TIMINGS);
+ ret = exynos5_switch_timing_regs(dmc, USE_BPLL_TIMINGS);
+ if (ret)
+ goto disable_clocks;
ret = clk_set_parent(dmc->mout_mclk_cdrex, dmc->mout_bpll);
if (ret)
--
2.17.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] memory: samsung: exynos5422-dmc: Do not ignore return code of regmap_read()
2020-07-20 11:03 [PATCH] memory: samsung: exynos5422-dmc: Do not ignore return code of regmap_read() Krzysztof Kozlowski
@ 2020-07-27 8:35 ` Lukasz Luba
0 siblings, 0 replies; 2+ messages in thread
From: Lukasz Luba @ 2020-07-27 8:35 UTC (permalink / raw)
To: Krzysztof Kozlowski, Kukjin Kim, linux-pm, linux-samsung-soc,
linux-arm-kernel, linux-kernel
Hi Krzysztof,
On 7/20/20 12:03 PM, Krzysztof Kozlowski wrote:
> Check for regmap_read() return code before using the read value in
> following write in exynos5_switch_timing_regs(). Pass reading error
> code to the callers.
>
> This does not introduce proper error handling for such failed reads (and
> obviously regmap_write() error is still ignored) because the driver
> ignored this in all places. Therefor it only fixes reported issue while
> matching current driver coding style:
>
> drivers/memory/samsung/exynos5422-dmc.c: In function 'exynos5_switch_timing_regs':
> >> drivers/memory/samsung/exynos5422-dmc.c:216:6: warning: variable 'ret' set but not used [-Wunused-but-set-variable]
>
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
> ---
> drivers/memory/samsung/exynos5422-dmc.c | 12 +++++++++---
> 1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/memory/samsung/exynos5422-dmc.c b/drivers/memory/samsung/exynos5422-dmc.c
> index 93e9c2429c0d..2c326998cb1c 100644
> --- a/drivers/memory/samsung/exynos5422-dmc.c
> +++ b/drivers/memory/samsung/exynos5422-dmc.c
> @@ -270,12 +270,14 @@ static int find_target_freq_idx(struct exynos5_dmc *dmc,
> * This function switches between these banks according to the
> * currently used clock source.
> */
> -static void exynos5_switch_timing_regs(struct exynos5_dmc *dmc, bool set)
> +static int exynos5_switch_timing_regs(struct exynos5_dmc *dmc, bool set)
> {
> unsigned int reg;
> int ret;
>
> ret = regmap_read(dmc->clk_regmap, CDREX_LPDDR3PHY_CON3, ®);
> + if (ret)
> + return ret;
>
> if (set)
> reg |= EXYNOS5_TIMING_SET_SWI;
> @@ -283,6 +285,8 @@ static void exynos5_switch_timing_regs(struct exynos5_dmc *dmc, bool set)
> reg &= ~EXYNOS5_TIMING_SET_SWI;
>
> regmap_write(dmc->clk_regmap, CDREX_LPDDR3PHY_CON3, reg);
> +
> + return 0;
> }
>
> /**
> @@ -516,7 +520,7 @@ exynos5_dmc_switch_to_bypass_configuration(struct exynos5_dmc *dmc,
> /*
> * Delays are long enough, so use them for the new coming clock.
> */
> - exynos5_switch_timing_regs(dmc, USE_MX_MSPLL_TIMINGS);
> + ret = exynos5_switch_timing_regs(dmc, USE_MX_MSPLL_TIMINGS);
>
> return ret;
> }
> @@ -577,7 +581,9 @@ exynos5_dmc_change_freq_and_volt(struct exynos5_dmc *dmc,
>
> clk_set_rate(dmc->fout_bpll, target_rate);
>
> - exynos5_switch_timing_regs(dmc, USE_BPLL_TIMINGS);
> + ret = exynos5_switch_timing_regs(dmc, USE_BPLL_TIMINGS);
> + if (ret)
> + goto disable_clocks;
>
> ret = clk_set_parent(dmc->mout_mclk_cdrex, dmc->mout_bpll);
> if (ret)
>
LGTM
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Regards,
Lukasz
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2020-07-20 11:03 [PATCH] memory: samsung: exynos5422-dmc: Do not ignore return code of regmap_read() Krzysztof Kozlowski
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