[PATCH v2] mmc: sdhci-esdhc-mcf: Flag the sg_miter as atomic

[PATCH v2] mmc: sdhci-esdhc-mcf: Flag the sg_miter as atomic

[Linus Walleij]

The sg_miter used to loop over the returned sglist from a
transfer in the esdhc subdriver for SDHCI can be called
from atomic context so the miter needs to be atomic.

sdhci_request_done() is always called from process context,
either as a work or as part of the threaded interrupt handler,
but the one case when we are actually calling .request_done()
from an atomic context is in sdhci_irq().

Fix this by flaggig the miter atomic so we always use
kmap_atomic().

Fixes: e8a167b84886 ("mmc: sdhci-esdhc-mcf: Use sg_miter for swapping")
Reported-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
Changes in v2:
- Do the simpler fix and just use an atomic iterator, it
  will work fine since esdhc_mcf_buffer_swap32() doesn't sleep.
- Link to v1: https://lore.kernel.org/r/20240222-fix-sdhci-esdhc-mcf-v1-1-fb87e04ca575@linaro.org
---
 drivers/mmc/host/sdhci-esdhc-mcf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sdhci-esdhc-mcf.c b/drivers/mmc/host/sdhci-esdhc-mcf.c
index 1909a11fd065..c97363e2d86c 100644
--- a/drivers/mmc/host/sdhci-esdhc-mcf.c
+++ b/drivers/mmc/host/sdhci-esdhc-mcf.c
@@ -313,7 +313,7 @@ static void esdhc_mcf_request_done(struct sdhci_host *host,
 	 * transfer endiannes. A swap after the transfer is needed.
 	 */
 	sg_miter_start(&sgm, mrq->data->sg, mrq->data->sg_len,
-		       SG_MITER_TO_SG | SG_MITER_FROM_SG);
+		       SG_MITER_ATOMIC | SG_MITER_TO_SG | SG_MITER_FROM_SG);
 	while (sg_miter_next(&sgm)) {
 		buffer = sgm.addr;
 		esdhc_mcf_buffer_swap32(buffer, sgm.length);

---
base-commit: 20af1ca418d2c0b11bc2a1fe8c0c88f67bcc2a7e
change-id: 20240228-fix-sdhci-esdhc-mcf-2-539cf338c3a3

Best regards,
-- 
Linus Walleij <linus.walleij@linaro.org>

Re: [PATCH v2] mmc: sdhci-esdhc-mcf: Flag the sg_miter as atomic

[Adrian Hunter]

On 28/02/24 11:07, Linus Walleij wrote:
> The sg_miter used to loop over the returned sglist from a
> transfer in the esdhc subdriver for SDHCI can be called
> from atomic context so the miter needs to be atomic.
> 
> sdhci_request_done() is always called from process context,
> either as a work or as part of the threaded interrupt handler,
> but the one case when we are actually calling .request_done()
> from an atomic context is in sdhci_irq().
> 
> Fix this by flaggig the miter atomic so we always use

flaggig -> flagging

> kmap_atomic().
> 
> Fixes: e8a167b84886 ("mmc: sdhci-esdhc-mcf: Use sg_miter for swapping")
> Reported-by: Adrian Hunter <adrian.hunter@intel.com>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

> ---
> Changes in v2:
> - Do the simpler fix and just use an atomic iterator, it
>   will work fine since esdhc_mcf_buffer_swap32() doesn't sleep.
> - Link to v1: https://lore.kernel.org/r/20240222-fix-sdhci-esdhc-mcf-v1-1-fb87e04ca575@linaro.org
> ---
>  drivers/mmc/host/sdhci-esdhc-mcf.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/sdhci-esdhc-mcf.c b/drivers/mmc/host/sdhci-esdhc-mcf.c
> index 1909a11fd065..c97363e2d86c 100644
> --- a/drivers/mmc/host/sdhci-esdhc-mcf.c
> +++ b/drivers/mmc/host/sdhci-esdhc-mcf.c
> @@ -313,7 +313,7 @@ static void esdhc_mcf_request_done(struct sdhci_host *host,
>  	 * transfer endiannes. A swap after the transfer is needed.
>  	 */
>  	sg_miter_start(&sgm, mrq->data->sg, mrq->data->sg_len,
> -		       SG_MITER_TO_SG | SG_MITER_FROM_SG);
> +		       SG_MITER_ATOMIC | SG_MITER_TO_SG | SG_MITER_FROM_SG);
>  	while (sg_miter_next(&sgm)) {
>  		buffer = sgm.addr;
>  		esdhc_mcf_buffer_swap32(buffer, sgm.length);
> 
> ---
> base-commit: 20af1ca418d2c0b11bc2a1fe8c0c88f67bcc2a7e
> change-id: 20240228-fix-sdhci-esdhc-mcf-2-539cf338c3a3
> 
> Best regards,

Re: [PATCH v2] mmc: sdhci-esdhc-mcf: Flag the sg_miter as atomic

[Ulf Hansson]

On Wed, 28 Feb 2024 at 10:07, Linus Walleij <linus.walleij@linaro.org> wrote:
>
> The sg_miter used to loop over the returned sglist from a
> transfer in the esdhc subdriver for SDHCI can be called
> from atomic context so the miter needs to be atomic.
>
> sdhci_request_done() is always called from process context,
> either as a work or as part of the threaded interrupt handler,
> but the one case when we are actually calling .request_done()
> from an atomic context is in sdhci_irq().
>
> Fix this by flaggig the miter atomic so we always use
> kmap_atomic().
>
> Fixes: e8a167b84886 ("mmc: sdhci-esdhc-mcf: Use sg_miter for swapping")
> Reported-by: Adrian Hunter <adrian.hunter@intel.com>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Applied for next and by fixing the spelling mistake in the commit
message, that was pointed out by Adrian, thanks!

Kind regards
Uffe


> ---
> Changes in v2:
> - Do the simpler fix and just use an atomic iterator, it
>   will work fine since esdhc_mcf_buffer_swap32() doesn't sleep.
> - Link to v1: https://lore.kernel.org/r/20240222-fix-sdhci-esdhc-mcf-v1-1-fb87e04ca575@linaro.org
> ---
>  drivers/mmc/host/sdhci-esdhc-mcf.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci-esdhc-mcf.c b/drivers/mmc/host/sdhci-esdhc-mcf.c
> index 1909a11fd065..c97363e2d86c 100644
> --- a/drivers/mmc/host/sdhci-esdhc-mcf.c
> +++ b/drivers/mmc/host/sdhci-esdhc-mcf.c
> @@ -313,7 +313,7 @@ static void esdhc_mcf_request_done(struct sdhci_host *host,
>          * transfer endiannes. A swap after the transfer is needed.
>          */
>         sg_miter_start(&sgm, mrq->data->sg, mrq->data->sg_len,
> -                      SG_MITER_TO_SG | SG_MITER_FROM_SG);
> +                      SG_MITER_ATOMIC | SG_MITER_TO_SG | SG_MITER_FROM_SG);
>         while (sg_miter_next(&sgm)) {
>                 buffer = sgm.addr;
>                 esdhc_mcf_buffer_swap32(buffer, sgm.length);
>
> ---
> base-commit: 20af1ca418d2c0b11bc2a1fe8c0c88f67bcc2a7e
> change-id: 20240228-fix-sdhci-esdhc-mcf-2-539cf338c3a3
>
> Best regards,
> --
> Linus Walleij <linus.walleij@linaro.org>
>