[PATCH] mmc: sunxi: mask all Response Timeout error messages

[icenowy@aosc.xyz (Icenowy Zheng)]

06.03.2017, 18:04, "Maxime Ripard" <maxime.ripard@free-electrons.com>:
> Hi,
>
> On Mon, Mar 06, 2017 at 12:45:35AM +0800, Icenowy Zheng wrote:
>> ?Response Timeout is very usual: it will happen when trying to run some
>> ?commands that do not belong to the card; it will happen when some SDIO
>> ?card transfer beyond its SDIO bandwidth; and when the MMC controller is
>> ?set to poll the card with "broken-cd" property (the Lichee Pi series of
>> ?boards do this), it will flood to the console and make the console
>> ?unusable.
>>
>> ?Mask all response-timeout-only error messages, only show it when another
>> ?error happens.
>>
>> ?Signed-off-by: Icenowy Zheng <icenowy@aosc.xyz>
>> ?---
>> ??drivers/mmc/host/sunxi-mmc.c | 13 +++++++++----
>> ??1 file changed, 9 insertions(+), 4 deletions(-)
>>
>> ?diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c
>> ?index 6ffcd2838272..7828e1f57cf0 100644
>> ?--- a/drivers/mmc/host/sunxi-mmc.c
>> ?+++ b/drivers/mmc/host/sunxi-mmc.c
>> ?@@ -483,10 +483,15 @@ static void sunxi_mmc_dump_errinfo(struct sunxi_mmc_host *host)
>> ??????????struct mmc_command *cmd = host->mrq->cmd;
>> ??????????struct mmc_data *data = host->mrq->data;
>>
>> ?- /* For some cmds timeout is normal with sd/mmc cards */
>> ?- if ((host->int_sum & SDXC_INTERRUPT_ERROR_BIT) ==
>> ?- SDXC_RESP_TIMEOUT && (cmd->opcode == SD_IO_SEND_OP_COND ||
>> ?- cmd->opcode == SD_IO_RW_DIRECT))
>> ?+ /*
>> ?+ * Reading timeout is usually normal, especially when doing
>> ?+ * card-polling with "broken-cd" in device tree.
>> ?+ * If do not mask it, the RTO error message will flood the console
>> ?+ * and even hide useful error messages.
>> ?+ *
>> ?+ * Some SDIO commands will also normally timeout with non-SDIO cards.
>> ?+ */
>> ?+ if ((host->int_sum & SDXC_INTERRUPT_ERROR_BIT) == SDXC_RESP_TIMEOUT)
>
> We really shouldn't silence legit errors.
>
> The actual problem here is that we log them as error, we could
> probably reduce it to debug.

Even if it's reduced to debug, it will still flush dmesg buffers.

Or make it only visible when "debug" parameter is present in kernel
cmdline?

>
> Maxime
>
> --
> Maxime Ripard, Free Electrons
> Embedded Linux and Kernel engineering
> http://free-electrons.com