Re: [PATCH 1/1] mmc: sdhci: check host->cmd is null or not in sdhci_cqe_irq()

[Adrian Hunter <adrian.hunter@intel.com>]

On 31/08/22 15:43, Ying-Chun Liu (PaulLiu) wrote:
> From: "Ying-Chun Liu (PaulLiu)" <paul.liu@linaro.org>
> 
> If we don't check host->cmd. We will get the following oops
> when booting from eMMC on RockPi4.
> 
>  Unable to handle kernel read from unreadable memory at
>    virtual address 0000000000000000
>  Call trace:
>    sdhci_cqe_irq+0x40/0x254

Thank you!  However, I prefer this patch:

https://lore.kernel.org/linux-mmc/20220907035847.13783-1-wenchao.chen666@gmail.com/

> 
> Signed-off-by: Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org>
> Signed-off-by: Ram Muthiah <rammuthiah@google.com>
> Cc: Adrian Hunter <adrian.hunter@intel.com>
> Cc: Ritesh Harjani <riteshh@codeaurora.org>
> Cc: Asutosh Das <asutoshd@codeaurora.org>
> Cc: Ulf Hansson <ulf.hansson@linaro.org>
> Cc: linux-mmc@vger.kernel.org
> ---
>  drivers/mmc/host/sdhci.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 7689ffec5ad1..e0e7768bd6c0 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -3928,7 +3928,7 @@ bool sdhci_cqe_irq(struct sdhci_host *host, u32 intmask, int *cmd_error,
>  
>  	if (intmask & (SDHCI_INT_INDEX | SDHCI_INT_END_BIT | SDHCI_INT_CRC)) {
>  		*cmd_error = -EILSEQ;
> -		if (!mmc_op_tuning(host->cmd->opcode))
> +		if (host->cmd && !mmc_op_tuning(host->cmd->opcode))
>  			sdhci_err_stats_inc(host, CMD_CRC);
>  	} else if (intmask & SDHCI_INT_TIMEOUT) {
>  		*cmd_error = -ETIMEDOUT;
> @@ -3938,7 +3938,7 @@ bool sdhci_cqe_irq(struct sdhci_host *host, u32 intmask, int *cmd_error,
>  
>  	if (intmask & (SDHCI_INT_DATA_END_BIT | SDHCI_INT_DATA_CRC)) {
>  		*data_error = -EILSEQ;
> -		if (!mmc_op_tuning(host->cmd->opcode))
> +		if (host->cmd && !mmc_op_tuning(host->cmd->opcode))
>  			sdhci_err_stats_inc(host, DAT_CRC);
>  	} else if (intmask & SDHCI_INT_DATA_TIMEOUT) {
>  		*data_error = -ETIMEDOUT;