kernel/linux.git/drivers/mmc/core/sdio_ops.c, branch linux-4.16.y

mmc: sdio: improve mmc_io_rw_extended

2017-04-24T19:41:42+00:00

Improve mmc_io_rw_extended a little: - using DIV_ROUND_UP achieves the same but is better readable - simplify code by using sg_set_buf - simplify one statement by using -= operator Signed-off-by: Heiner Kallweit Signed-off-by: Ulf Hansson

mmc: use empty initializer list to zero-clear structures

2017-02-13T12:19:54+00:00

In the MMC subsystem, we see such initializers that only clears the first member explicitly. For example, struct mmc_request mrq = {NULL}; sets the first member (.sbc) to NULL explicitly. However, this is an unstable form because we may insert a non-pointer member at the top of the struct mmc_request in the future. (if we do so, the compiler will spit warnings.) So, using a designated initializer is preferred coding style. The expression above is equivalent to: struct mmc_request mrq = { .sbc = NULL }; Of course, this does not express our intention. We want to fill all struct members with zeros. Please note struct members are implicitly zero-cleared unless otherwise specified in the initializer. After all, the most reasonable (and stable) form is: struct mmc_request mrq = {}; Do likewise for mmc_command, mmc_data as well. Signed-off-by: Masahiro Yamada Reviewed-by: Linus Walleij Signed-off-by: Ulf Hansson

mmc: sdio: deploy error handling instead of triggering BUG_ON

2016-09-26T19:31:15+00:00

When using mmc_io_rw_extended, it's intent to avoid null pointer of card and invalid func number. But actually it didn't prevent that as the seg_size already use the card. Currently the wrapper function sdio_io_rw_ext_helper already use card before calling mmc_io_rw_extended, so we should move this check to there. As to the func number, it was token from '(ocr & 0x70000000) >> 28' which should be enough to guarantee that it won't be larger than 7. But we should prevent the caller like wifi drivers modify this value. So let's move this check into sdio_io_rw_ext_helper either. Also we remove the BUG_ON for mmc_send_io_op_cond since all possible paths calling this function are protected by checking the arguments in advance. After deploying these changes, we could not see any panic within SDIO API even if func drivers abuse the SDIO func APIs. Signed-off-by: Shawn Lin Signed-off-by: Ulf Hansson

mmc: remove unnecessary assignment statements before return

2016-02-29T10:02:47+00:00

Variable assignment just before return is redundant. Signed-off-by: Masahiro Yamada Signed-off-by: Ulf Hansson

mmc: sdio: Use multiple scatter/gather list

2012-12-06T18:54:43+00:00

Before this patch, we always used only single sg entry for SDIO transfer. This patch switches to using multiple sg entries. In the case of dwmci, it supports only up to 4KB size per single sg entry. So if we want to transfer more than 4KB, we should send more than 1 command. When we tested before applying this patch, it took around 335 us for 5K(5120) bytes transfer with dwmci controller. After applying this patch, it takes 242 us for 5K bytes. So this patch makes around 38% performance improvement for 5K bytes transfer. If the transfer size is bigger, then the performance improvement ratio will be increased. Signed-off-by: Kyoungil Kim Signed-off-by: Chris Ball

mmc: sdio: Fix to support any block size optimally

2012-01-12T04:58:40+00:00

This patch allows any block size to be set on the SDIO link, and still have an arbitrary sized packet (adjusted in size by using sdio_align_size) transferred in an optimal way (preferably one transfer). Previously if the block size was larger than the default of 512 bytes and the transfer size was exactly one block size (possibly thanks to using sdio_align_size to get an optimal transfer size), it was sent as a number of byte transfers instead of one block transfer. Also if the number of blocks was (max_blocks * N) + 1, the tranfer would be conducted with a number of blocks and finished off with a number of byte transfers. When doing this change it was also possible to break out the quirk for broken byte mode in a much cleaner way, and collect the logic of when to do byte or block transfer in one function instead of two. Signed-off-by: Stefan Nilsson XK Signed-off-by: Ulf Hansson Acked-by: Linus Walleij Signed-off-by: Chris Ball

mmc: sdio: Workaround for dev with broken CMD53

2011-10-26T20:32:02+00:00

Adds a quirk which can be turned on for SDIO devices that do not support 512 byte requests in byte mode during CMD53. These requests will always be sent in block mode instead. This patch also enables this quirk for ST-Ericsson CW1200 WLAN device. Signed-off-by: Stefan Nilsson XK Signed-off-by: Ulf HANSSON Acked-by: Linus Walleij Signed-off-by: Chris Ball

mmc: fix integer assignments to pointer

2011-10-26T19:43:35+00:00

Fix the sparse warning output "warning: Using plain integer as NULL pointer" Signed-off-by: Venkatraman S Signed-off-by: Chris Ball

mmc: initialize struct mmc_request at declaration time

2011-05-25T01:02:01+00:00

Converts from: struct mmc_request mrq; memset(&mrq, 0, sizeof(struct mmc_request)); to: struct mmc_request mrq = {0}; because it's shorter, as performant, and easier to work out whether initialization has happened. Signed-off-by: Chris Ball

mmc: initialize struct mmc_data at declaration time

2011-05-25T01:01:56+00:00

Converts from: struct mmc_data data; memset(&data, 0, sizeof(struct mmc_data)); to: struct mmc_data data = {0}; because it's shorter, as performant, and easier to work out whether initialization has happened. Signed-off-by: Chris Ball