From e027e72ecc1683e04f33aedf0196ad6c3278d309 Mon Sep 17 00:00:00 2001 From: Sergei Antonov Date: Mon, 22 Apr 2024 18:36:07 +0300 Subject: [PATCH] mmc: moxart: fix handling of sgm->consumed, otherwise WARN_ON triggers 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 Cc: Linus Walleij Fixes: 3ee0e7c3e67c ("mmc: moxart-mmc: Use sg_miter for PIO") Reviewed-by: Linus Walleij Link: https://lore.kernel.org/r/20240422153607.963672-1-saproj@gmail.com Signed-off-by: Ulf Hansson --- 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) { -- 2.25.1