Tejun Heo wrote:
For misc ATAPI commands which transfer variable length data to the
host, overflow can occur due to application or hardware bug. Such
overflows can be ignored safely as long as overflow data is properly
drained. libata HSM implementation has this implemented in
__atapi_pio_bytes() but it isn't enough. Improve drain logic such
that...
* Multiple PIO data phases are allowed. Not allowing this used to be
okay when transfer chunk size was set to 8k unconditionally but with
transfer hcunk size set to allocation size, treating extra PIO data
phases as HSM violations cause a lot of trouble.
* Limit the amount of draining to ATAPI_MAX_DRAIN (16k currently).
* Don't whine if overflow is allowed and safe. When unexpected
overflow occurs, trigger HSM violation and report the problem using
ehi error description.
* Properly calculate the number of bytes to be drained considering
actual number of consumed bytes for partial draining.
* Add and use ata_drain_page for draining. This change fixes the
problem where LLDs which do 32bit IOs consumes 4 bytes on each 2
byte draining resulting in draining twice more data than requested.
This patch fixes ATAPI regressions introduced by setting transfer
chunk size to allocation size.
Signed-off-by: Tejun Heo <[EMAIL PROTECTED]>
Cc: Albert Lee <[EMAIL PROTECTED]>
I'm dropping this one, since a good portion of it is already upstream
as140b5e59119a172a91b5fa13d54ca4f79bbefee1
Jeff
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