This is a note to let you know that I've just added the patch titled mmc: meson-mx-sdio: remove the broken ->card_busy() op to the 5.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mmc-meson-mx-sdio-remove-the-broken-card_busy-op.patch and it can be found in the queue-5.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From ddca1092c4324c89cf692b5efe655aa251864b51 Mon Sep 17 00:00:00 2001 From: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx> Date: Thu, 16 Apr 2020 20:35:13 +0200 Subject: mmc: meson-mx-sdio: remove the broken ->card_busy() op From: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx> commit ddca1092c4324c89cf692b5efe655aa251864b51 upstream. The recent commit 0d84c3e6a5b2 ("mmc: core: Convert to mmc_poll_for_busy() for erase/trim/discard") makes use of the ->card_busy() op for SD cards. This uncovered that the ->card_busy() op in the Meson SDIO driver was never working right: while polling the busy status with ->card_busy() meson_mx_mmc_card_busy() reads only one of the two MESON_MX_SDIO_IRQC register values 0x1f001f10 or 0x1f003f10. This translates to "three out of four DAT lines are HIGH" and "all four DAT lines are HIGH", which is interpreted as "the card is busy". It turns out that no situation can be observed where all four DAT lines are LOW, meaning the card is not busy anymore. Upon further research the 3.10 vendor driver for this controller does not implement the ->card_busy() op. Remove the ->card_busy() op from the meson-mx-sdio driver since it is not working. At the time of writing this patch it is not clear what's needed to make the ->card_busy() implementation work with this specific controller hardware. For all use-cases which have previously worked the MMC_CAP_WAIT_WHILE_BUSY flag is now taking over, even if we don't have a ->card_busy() op anymore. Fixes: ed80a13bb4c4c9 ("mmc: meson-mx-sdio: Add a driver for the Amlogic Meson8 and Meson8b SoCs") Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Link: https://lore.kernel.org/r/20200416183513.993763-3-martin.blumenstingl@xxxxxxxxxxxxxx Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/mmc/host/meson-mx-sdio.c | 9 --------- 1 file changed, 9 deletions(-) --- a/drivers/mmc/host/meson-mx-sdio.c +++ b/drivers/mmc/host/meson-mx-sdio.c @@ -357,14 +357,6 @@ static void meson_mx_mmc_request(struct meson_mx_mmc_start_cmd(mmc, mrq->cmd); } -static int meson_mx_mmc_card_busy(struct mmc_host *mmc) -{ - struct meson_mx_mmc_host *host = mmc_priv(mmc); - u32 irqc = readl(host->base + MESON_MX_SDIO_IRQC); - - return !!(irqc & MESON_MX_SDIO_IRQC_FORCE_DATA_DAT_MASK); -} - static void meson_mx_mmc_read_response(struct mmc_host *mmc, struct mmc_command *cmd) { @@ -506,7 +498,6 @@ static void meson_mx_mmc_timeout(struct static struct mmc_host_ops meson_mx_mmc_ops = { .request = meson_mx_mmc_request, .set_ios = meson_mx_mmc_set_ios, - .card_busy = meson_mx_mmc_card_busy, .get_cd = mmc_gpio_get_cd, .get_ro = mmc_gpio_get_ro, }; Patches currently in stable-queue which might be from martin.blumenstingl@xxxxxxxxxxxxxx are queue-5.6/mmc-meson-mx-sdio-set-mmc_cap_wait_while_busy.patch queue-5.6/mmc-meson-mx-sdio-remove-the-broken-card_busy-op.patch