On Mon, 22 Apr 2024 at 17:36, Sergei Antonov <saproj@xxxxxxxxx> wrote:
>
> When e.g. 8 bytes are to be read, sgm->consumed equals 8 immediately after
> sg_miter_next() call. The driver then increments it as bytes are read,
> so sgm->consumed becomes 16 and this warning triggers in sg_miter_stop():
> WARN_ON(miter->consumed > miter->length);
>
> WARNING: CPU: 0 PID: 28 at lib/scatterlist.c:925 sg_miter_stop+0x2c/0x10c
> CPU: 0 PID: 28 Comm: kworker/0:2 Tainted: G W 6.9.0-rc5-dirty #249
> Hardware name: Generic DT based system
> Workqueue: events_freezable mmc_rescan
> Call trace:.
> unwind_backtrace from show_stack+0x10/0x14
> show_stack from dump_stack_lvl+0x44/0x5c
> dump_stack_lvl from __warn+0x78/0x16c
> __warn from warn_slowpath_fmt+0xb0/0x160
> warn_slowpath_fmt from sg_miter_stop+0x2c/0x10c
> sg_miter_stop from moxart_request+0xb0/0x468
> moxart_request from mmc_start_request+0x94/0xa8
> mmc_start_request from mmc_wait_for_req+0x60/0xa8
> mmc_wait_for_req from mmc_app_send_scr+0xf8/0x150
> mmc_app_send_scr from mmc_sd_setup_card+0x1c/0x420
> mmc_sd_setup_card from mmc_sd_init_card+0x12c/0x4dc
> mmc_sd_init_card from mmc_attach_sd+0xf0/0x16c
> mmc_attach_sd from mmc_rescan+0x1e0/0x298
> mmc_rescan from process_scheduled_works+0x2e4/0x4ec
> process_scheduled_works from worker_thread+0x1ec/0x24c
> worker_thread from kthread+0xd4/0xe0
> kthread from ret_from_fork+0x14/0x38
>
> This patch adds initial zeroing of sgm->consumed. It is then incremented
> as bytes are read or written.
>
> Signed-off-by: Sergei Antonov <saproj@xxxxxxxxx>
> Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
> Fixes: 3ee0e7c3e67c ("mmc: moxart-mmc: Use sg_miter for PIO")
Applied for fixes, thanks!
Kind regards
Uffe
> ---
> drivers/mmc/host/moxart-mmc.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/mmc/host/moxart-mmc.c b/drivers/mmc/host/moxart-mmc.c
> index b88d6dec209f..9a5f75163aca 100644
> --- a/drivers/mmc/host/moxart-mmc.c
> +++ b/drivers/mmc/host/moxart-mmc.c
> @@ -300,6 +300,7 @@ static void moxart_transfer_pio(struct moxart_host *host)
> remain = sgm->length;
> if (remain > host->data_len)
> remain = host->data_len;
> + sgm->consumed = 0;
>
> if (data->flags & MMC_DATA_WRITE) {
> while (remain > 0) {
> --
> 2.40.1
>
>
