[PATCH v2] mmc: core: Normalize the error handling branch in sd_read_ext_regs()

[PATCH v2] mmc: core: Normalize the error handling branch in sd_read_ext_regs()

[Zhen Lei]

1. Use pr_err() to output the error message.
2. Add the description of why success 0 is returned in case
   "non-supported SD ext reg layout".

Fixes: c784f92769ae ("mmc: core: Read the SD function extension registers for power management")
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
---
 drivers/mmc/core/sd.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 3662bf5320ce56d..93ee53f74427c38 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -1259,7 +1259,7 @@ static int sd_read_ext_regs(struct mmc_card *card)
 	 */
 	err = sd_read_ext_reg(card, 0, 0, 0, 512, gen_info_buf);
 	if (err) {
-		pr_warn("%s: error %d reading general info of SD ext reg\n",
+		pr_err("%s: error %d reading general info of SD ext reg\n",
 			mmc_hostname(card->host), err);
 		goto out;
 	}
@@ -1273,7 +1273,12 @@ static int sd_read_ext_regs(struct mmc_card *card)
 	/* Number of extensions to be find. */
 	num_ext = gen_info_buf[4];
 
-	/* We support revision 0, but limit it to 512 bytes for simplicity. */
+	/*
+	 * We only support revision 0, and limit it to 512 bytes for simplicity.
+	 * In other cases, success 0 is returned, because the card remains
+	 * functional and all but the new features from the SD function
+	 * extensions registers can still be used.
+	 */
 	if (rev != 0 || len > 512) {
 		pr_warn("%s: non-supported SD ext reg layout\n",
 			mmc_hostname(card->host));
@@ -1288,7 +1293,7 @@ static int sd_read_ext_regs(struct mmc_card *card)
 	for (i = 0; i < num_ext; i++) {
 		err = sd_parse_ext_reg(card, gen_info_buf, &next_ext_addr);
 		if (err) {
-			pr_warn("%s: error %d parsing SD ext reg\n",
+			pr_err("%s: error %d parsing SD ext reg\n",
 				mmc_hostname(card->host), err);
 			goto out;
 		}
-- 
2.25.1

Re: [PATCH v2] mmc: core: Normalize the error handling branch in sd_read_ext_regs()

[Leizhen (ThunderTown)]

On 2022/11/30 21:49, Zhen Lei wrote:
> 1. Use pr_err() to output the error message.
> 2. Add the description of why success 0 is returned in case
>    "non-supported SD ext reg layout".
> 
> Fixes: c784f92769ae ("mmc: core: Read the SD function extension registers for power management")
> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
> ---
>  drivers/mmc/core/sd.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)

Sorry, I forgot to add the version difference description.

v1 --> v2:
Add a description instead of returning an error code.

v1:
https://lkml.org/lkml/2022/11/30/240

> 
> diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
> index 3662bf5320ce56d..93ee53f74427c38 100644
> --- a/drivers/mmc/core/sd.c
> +++ b/drivers/mmc/core/sd.c
> @@ -1259,7 +1259,7 @@ static int sd_read_ext_regs(struct mmc_card *card)
>  	 */
>  	err = sd_read_ext_reg(card, 0, 0, 0, 512, gen_info_buf);
>  	if (err) {
> -		pr_warn("%s: error %d reading general info of SD ext reg\n",
> +		pr_err("%s: error %d reading general info of SD ext reg\n",
>  			mmc_hostname(card->host), err);
>  		goto out;
>  	}
> @@ -1273,7 +1273,12 @@ static int sd_read_ext_regs(struct mmc_card *card)
>  	/* Number of extensions to be find. */
>  	num_ext = gen_info_buf[4];
>  
> -	/* We support revision 0, but limit it to 512 bytes for simplicity. */
> +	/*
> +	 * We only support revision 0, and limit it to 512 bytes for simplicity.
> +	 * In other cases, success 0 is returned, because the card remains
> +	 * functional and all but the new features from the SD function
> +	 * extensions registers can still be used.
> +	 */
>  	if (rev != 0 || len > 512) {
>  		pr_warn("%s: non-supported SD ext reg layout\n",
>  			mmc_hostname(card->host));
> @@ -1288,7 +1293,7 @@ static int sd_read_ext_regs(struct mmc_card *card)
>  	for (i = 0; i < num_ext; i++) {
>  		err = sd_parse_ext_reg(card, gen_info_buf, &next_ext_addr);
>  		if (err) {
> -			pr_warn("%s: error %d parsing SD ext reg\n",
> +			pr_err("%s: error %d parsing SD ext reg\n",
>  				mmc_hostname(card->host), err);
>  			goto out;
>  		}
> 

-- 
Regards,
  Zhen Lei

Re: [PATCH v2] mmc: core: Normalize the error handling branch in sd_read_ext_regs()

[Ulf Hansson]

On Wed, 30 Nov 2022 at 14:49, Zhen Lei <thunder.leizhen@huawei.com> wrote:
>
> 1. Use pr_err() to output the error message.
> 2. Add the description of why success 0 is returned in case
>    "non-supported SD ext reg layout".
>
> Fixes: c784f92769ae ("mmc: core: Read the SD function extension registers for power management")
> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>

Applied for next, thanks!

Kind regards
Uffe


> ---
>  drivers/mmc/core/sd.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
> index 3662bf5320ce56d..93ee53f74427c38 100644
> --- a/drivers/mmc/core/sd.c
> +++ b/drivers/mmc/core/sd.c
> @@ -1259,7 +1259,7 @@ static int sd_read_ext_regs(struct mmc_card *card)
>          */
>         err = sd_read_ext_reg(card, 0, 0, 0, 512, gen_info_buf);
>         if (err) {
> -               pr_warn("%s: error %d reading general info of SD ext reg\n",
> +               pr_err("%s: error %d reading general info of SD ext reg\n",
>                         mmc_hostname(card->host), err);
>                 goto out;
>         }
> @@ -1273,7 +1273,12 @@ static int sd_read_ext_regs(struct mmc_card *card)
>         /* Number of extensions to be find. */
>         num_ext = gen_info_buf[4];
>
> -       /* We support revision 0, but limit it to 512 bytes for simplicity. */
> +       /*
> +        * We only support revision 0, and limit it to 512 bytes for simplicity.
> +        * In other cases, success 0 is returned, because the card remains
> +        * functional and all but the new features from the SD function
> +        * extensions registers can still be used.
> +        */
>         if (rev != 0 || len > 512) {
>                 pr_warn("%s: non-supported SD ext reg layout\n",
>                         mmc_hostname(card->host));
> @@ -1288,7 +1293,7 @@ static int sd_read_ext_regs(struct mmc_card *card)
>         for (i = 0; i < num_ext; i++) {
>                 err = sd_parse_ext_reg(card, gen_info_buf, &next_ext_addr);
>                 if (err) {
> -                       pr_warn("%s: error %d parsing SD ext reg\n",
> +                       pr_err("%s: error %d parsing SD ext reg\n",
>                                 mmc_hostname(card->host), err);
>                         goto out;
>                 }
> --
> 2.25.1
>