Messages in this thread Patch in this message | | | From | Pan Zhang <> | Subject | Re: Re: [PATCH] mmc: host: use kzalloc instead of kmalloc and memset | Date | Tue, 17 Dec 2019 22:17:33 +0800 |
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On Tue, 17 Dec 2019, 15:33 Greg KH <gregkh@linuxfoundation.org> wrote: >> Signed-off-by: Pan Zhang <zhangpan26@huawei.com> >> --- >> drivers/mmc/host/vub300.c | 4 +--- >> 1 file changed, 1 insertion(+), 3 deletions(-)
>I know I can not take patches without any changelog text, hopefully other maintainers also do the same.
>Please fix,
and
>> Signed-off-by: Pan Zhang <zhangpan26@huawei.com> >> --- >> drivers/mmc/host/vub300.c | 12 ++++-------- >> 1 file changed, 4 insertions(+), 8 deletions(-)
>What changed from v1? Always put that below the --- line.
I am so sorry about that I didnot explain this patch clearly. I complemented patch v2 just after sending the patch v1 because I found that following code has similar problems.
My changelog text can be also my reply to the following question:
On Tue, 17 Dec 2019, 15:32 David Rientjes <rientjes@google.com> wrote: >I think the previous code is an optimization since the first interrupt_size bytes >or ts bytes of xfer_buffer would otherwise unnecessarily be zeroed and then copied to.
Part of the memory will be written twice after this change, but that should be negligible. 1. xfer_buffer or xfer_buffer - interrupt_size, it won't be big. 2. __download_offload_pseudocode func wouldnot be called frequently.
Signed-off-by: Pan Zhang <zhangpan26@huawei.com> --- drivers/mmc/host/vub300.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-)
diff --git a/drivers/mmc/host/vub300.c b/drivers/mmc/host/vub300.c index 6ced1b7..e18931d 100644 --- a/drivers/mmc/host/vub300.c +++ b/drivers/mmc/host/vub300.c @@ -1227,12 +1227,10 @@ static void __download_offload_pseudocode(struct vub300_mmc_host *vub300, size -= 1; if (interrupt_size < size) { u16 xfer_length = roundup_to_multiple_of_64(interrupt_size); - u8 *xfer_buffer = kmalloc(xfer_length, GFP_KERNEL); + u8 *xfer_buffer = kzalloc(xfer_length, GFP_KERNEL); if (xfer_buffer) { int retval; memcpy(xfer_buffer, data, interrupt_size); - memset(xfer_buffer + interrupt_size, 0, - xfer_length - interrupt_size); size -= interrupt_size; data += interrupt_size; retval = @@ -1270,12 +1268,10 @@ static void __download_offload_pseudocode(struct vub300_mmc_host *vub300, size -= 1; if (ts < size) { u16 xfer_length = roundup_to_multiple_of_64(ts); - u8 *xfer_buffer = kmalloc(xfer_length, GFP_KERNEL); + u8 *xfer_buffer = kzalloc(xfer_length, GFP_KERNEL); if (xfer_buffer) { int retval; memcpy(xfer_buffer, data, ts); - memset(xfer_buffer + ts, 0, - xfer_length - ts); size -= ts; data += ts; retval = @@ -1465,7 +1461,7 @@ static int __command_read_data(struct vub300_mmc_host *vub300, } } } else { - u8 *buf = kmalloc(padded_length, GFP_KERNEL); + u8 *buf = kzalloc(padded_length, GFP_KERNEL); if (buf) { int result; unsigned pipe = usb_rcvbulkpipe(vub300->udev, @@ -2024,7 +2020,7 @@ static void vub300_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) msleep(600); vub300->card_powered = 1; } else if (ios->power_mode == MMC_POWER_ON) { - u8 *buf = kmalloc(8, GFP_KERNEL); + u8 *buf = kzalloc(8, GFP_KERNEL); if (buf) { __set_clock_speed(vub300, buf, ios); kfree(buf); -- 2.7.4
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