kernel/linux.git/drivers/mmc/core/mmc.c, branch linux-4.7.y

mmc: fix mmc mode selection for HS-DDR and higher

2016-06-02T08:39:05+00:00

When IS_ERR_VALUE was removed from the mmc core code, it was replaced with a simple not-zero check. This does not work, as the value checked is the return value for mmc_select_bus_width, which returns the set bit width on success. This made eMMC modes higher than HS-DDR unusable. Fix this by checking for a positive return value instead. Fixes: 287980e49ffc ("remove lots of IS_ERR_VALUE abuses") Cc: Arnd Bergmann Signed-off-by: Chen-Yu Tsai Acked-by: Hans de Goede Reviewed-by: Krzysztof Kozlowski Acked-by: Jaehoon Chung Reviewed-by: Shawn Lin Tested-by: Marcel Ziswiler Tested-by: Bjorn Andersson Signed-off-by: Ulf Hansson

remove lots of IS_ERR_VALUE abuses

2016-05-27T22:26:11+00:00

Most users of IS_ERR_VALUE() in the kernel are wrong, as they pass an 'int' into a function that takes an 'unsigned long' argument. This happens to work because the type is sign-extended on 64-bit architectures before it gets converted into an unsigned type. However, anything that passes an 'unsigned short' or 'unsigned int' argument into IS_ERR_VALUE() is guaranteed to be broken, as are 8-bit integers and types that are wider than 'unsigned long'. Andrzej Hajda has already fixed a lot of the worst abusers that were causing actual bugs, but it would be nice to prevent any users that are not passing 'unsigned long' arguments. This patch changes all users of IS_ERR_VALUE() that I could find on 32-bit ARM randconfig builds and x86 allmodconfig. For the moment, this doesn't change the definition of IS_ERR_VALUE() because there are probably still architecture specific users elsewhere. Almost all the warnings I got are for files that are better off using 'if (err)' or 'if (err < 0)'. The only legitimate user I could find that we get a warning for is the (32-bit only) freescale fman driver, so I did not remove the IS_ERR_VALUE() there but changed the type to 'unsigned long'. For 9pfs, I just worked around one user whose calling conventions are so obscure that I did not dare change the behavior. I was using this definition for testing: #define IS_ERR_VALUE(x) ((unsigned long*)NULL == (typeof (x)*)NULL && \ unlikely((unsigned long long)(x) >= (unsigned long long)(typeof(x))-MAX_ERRNO)) which ends up making all 16-bit or wider types work correctly with the most plausible interpretation of what IS_ERR_VALUE() was supposed to return according to its users, but also causes a compile-time warning for any users that do not pass an 'unsigned long' argument. I suggested this approach earlier this year, but back then we ended up deciding to just fix the users that are obviously broken. After the initial warning that caused me to get involved in the discussion (fs/gfs2/dir.c) showed up again in the mainline kernel, Linus asked me to send the whole thing again. [ Updated the 9p parts as per Al Viro - Linus ] Signed-off-by: Arnd Bergmann Cc: Andrzej Hajda Cc: Andrew Morton Link: https://lkml.org/lkml/2016/1/7/363 Link: https://lkml.org/lkml/2016/5/27/486 Acked-by: Srinivas Kandagatla # For nvmem part Signed-off-by: Linus Torvalds

mmc: mmc: Fix partition switch timeout for some eMMCs

2016-05-16T09:31:28+00:00

Some eMMCs set the partition switch timeout too low. Now typically eMMCs are considered a critical component (e.g. because they store the root file system) and consequently are expected to be reliable. Thus we can neglect the use case where eMMCs can't switch reliably and we might want a lower timeout to facilitate speedy recovery. Although we could employ a quirk for the cards that are affected (if we could identify them all), as described above, there is little benefit to having a low timeout, so instead simply set a minimum timeout. The minimum is set to 300ms somewhat arbitrarily - the examples that have been seen had a timeout of 10ms but were sometimes taking 60-70ms. Cc: stable@vger.kernel.org Signed-off-by: Adrian Hunter Signed-off-by: Ulf Hansson

mmc: core: remove the invalid message in mmc_select_timing

2016-05-10T08:37:59+00:00

mmc_select_hs200() and mmc_select_hs() will keep the timing as before if switch fails. So it's meaningless to print the failed switched mode outside based on the current host timing. Furthermore, the original print is wrong, it should be: pr_warn("%s: switch to %s failed\n", mmc_hostname(card->host), mmc_card_hs(card) ? "high-speed" : (mmc_card_hs200(card) ? "hs200" : "")); Since we already have error message in mmc_select_hs200(), simply remove it outside. Signed-off-by: Dong Aisheng Signed-off-by: Ulf Hansson

mmc: core: fix using wrong io voltage if mmc_select_hs200 fails

2016-05-10T08:37:01+00:00

Currently MMC core will keep going if HS200/HS timing switch failed with -EBADMSG error by the assumption that the old timing is still valid. However, for mmc_select_hs200 case, the signal voltage may have already been switched. If the timing switch failed, we should fall back to the old voltage in case the card is continue run with legacy timing. If fall back signal voltage failed, we explicitly report an EIO error to force retry during the next power cycle. Signed-off-by: Dong Aisheng Signed-off-by: Ulf Hansson

mmc: mmc: Attempt to flush cache before reset

2016-05-04T11:11:53+00:00

CMD0 or hardware reset may invalidate the cache, so it needs to be flushed before reset. In the case of recovery, we can't expect flushing the cache to work always, but have a go and ignore errors. Signed-off-by: Adrian Hunter Signed-off-by: Ulf Hansson

mmc: core: drop unnecessary bit checking

2016-05-02T08:33:31+00:00

This if-block is going to call mmc_card_set_blockaddr(), so mmc_card_blockaddr() right before it is redundant. I am fixing the block comment style while I am here. Signed-off-by: Masahiro Yamada Signed-off-by: Ulf Hansson

mmc: core: Do regular power cycle when lacking eMMC HW reset support

2016-05-02T08:33:24+00:00

The eMMC HW reset may be implemented either via the host ops ->hw_reset() callback or through DT and the eMMC pwrseq. Additionally some eMMC cards don't support HW reset. To allow a reset to be done for the different combinations of mmc hosts and eMMC/MMC cards, let's implement a fallback via trying a regular power cycle. This improves the mmc block layer retry mechanism of failing I/O requests. Signed-off-by: Gwendal Grignou [Ulf: Rewrote changelog] Signed-off-by: Ulf Hansson

mmc: sanitize 'bus width' in debug output

2016-02-29T10:02:56+00:00

The bus width is sometimes the actual bus width, and sometimes indices to different arrays encoding the bus width. In my debugging case "2" could mean 8-bit as well as 4-bit, which was extremly confusing. Let's use the human-readable actual bus width in all places. Signed-off-by: Wolfram Sang Signed-off-by: Ulf Hansson

mmc: make MAN_BKOPS_EN message a debug

2016-02-29T10:02:53+00:00

IMO this info is only useful for developers. Most users won't need this information, since there is not much they can do about it. Signed-off-by: Wolfram Sang Signed-off-by: Ulf Hansson