At http://dev.laptop.org/ticket/9707 we are seeing a crash in the error path of mmc_attach_sdio() BUG: unable to handle kernel paging request at 6b6b6c57 IP: [<b066d6e2>] sdio_remove_func+0x9/0x27 Call Trace: [<b066cfb4>] ? mmc_sdio_remove+0x34/0x65 [<b066d1fc>] ? mmc_attach_sdio+0x217/0x240 [<b066a22f>] ? mmc_rescan+0x1a2/0x20f [<b042e9a0>] ? worker_thread+0x156/0x1e1 Matt Fleming pointed out that this is because more cards are being removed than have been initialized/added in the error path. Fix the error path to handle failures gracefully. Based on earlier patch from Matt. Signed-off-by: Daniel Drake <dsd@xxxxxxxxxx> --- drivers/mmc/core/sdio.c | 6 ++++-- drivers/mmc/core/sdio_bus.c | 7 +++++-- 2 files changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c index cdb845b..fa07d4f 100644 --- a/drivers/mmc/core/sdio.c +++ b/drivers/mmc/core/sdio.c @@ -516,7 +516,8 @@ int mmc_attach_sdio(struct mmc_host *host, u32 ocr) * The number of functions on the card is encoded inside * the ocr. */ - card->sdio_funcs = funcs = (ocr & 0x70000000) >> 28; + funcs = (ocr & 0x70000000) >> 28; + card->sdio_funcs = 0; /* * If needed, disconnect card detection pull-up resistor. @@ -528,10 +529,11 @@ int mmc_attach_sdio(struct mmc_host *host, u32 ocr) /* * Initialize (but don't add) all present functions. */ - for (i = 0;i < funcs;i++) { + for (i = 0;i < funcs;i++, card->sdio_funcs++) { err = sdio_init_func(host->card, i + 1); if (err) goto remove; + card->sdio_funcs = i + 1; } mmc_release_host(host); diff --git a/drivers/mmc/core/sdio_bus.c b/drivers/mmc/core/sdio_bus.c index d37464e..9e060c8 100644 --- a/drivers/mmc/core/sdio_bus.c +++ b/drivers/mmc/core/sdio_bus.c @@ -248,12 +248,15 @@ int sdio_add_func(struct sdio_func *func) /* * Unregister a SDIO function with the driver model, and * (eventually) free it. + * This function can be called through error paths where sdio_add_func() was + * never executed (because a failure occurred at an earlier point). */ void sdio_remove_func(struct sdio_func *func) { - if (sdio_func_present(func)) - device_del(&func->dev); + if (!sdio_func_present(func)) + return; + device_del(&func->dev); put_device(&func->dev); } -- 1.6.2.5 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
