* [U-Boot] [PATCH v2] OMAP3 MMC: Fix warning dereferencing type-punned pointer
@ 2009-09-25 18:30 Dirk Behme
2009-09-25 20:08 ` Tom
0 siblings, 1 reply; 4+ messages in thread
From: Dirk Behme @ 2009-09-25 18:30 UTC (permalink / raw)
To: u-boot
Fix warning
dereferencing type-punned pointer will break strict-aliasing rules
Signed-off-by: Dirk Behme <dirk.behme@googlemail.com>
CC: Steve Sakoman <sakoman@gmail.com>
---
Changes in v2: Union elements mmc_resp_r3 and mmc_resp_r6 are no pointers.
v1 of this patch breaks MMC handling. Please revert v1 in u-boot-ti
http://git.denx.de/?p=u-boot/u-boot-ti.git;a=commit;h=eb19df366587c887a406d1816fa7f7dca07f537d
and use this one. Thanks to Steve Sakoman for reporting this!
Compile and boot tested on BeagleBoard.
drivers/mmc/omap3_mmc.c | 56 ++++++++++++++++++++++++------------------------
1 file changed, 29 insertions(+), 27 deletions(-)
Index: u-boot-ti/drivers/mmc/omap3_mmc.c
===================================================================
--- u-boot-ti.orig/drivers/mmc/omap3_mmc.c
+++ u-boot-ti/drivers/mmc/omap3_mmc.c
@@ -235,8 +235,13 @@ unsigned char mmc_detect_card(mmc_card_d
unsigned char err;
unsigned int argument = 0;
unsigned int ocr_value, ocr_recvd, ret_cmd41, hcs_val;
- unsigned int resp[4];
unsigned short retry_cnt = 2000;
+ union {
+ unsigned int resp[4];
+ mmc_resp_r3 r3;
+ mmc_resp_r6 r6;
+ } mmc_resp;
+
/* Set to Initialization Clock */
err = mmc_clock_config(CLK_400KHZ, 0);
@@ -247,18 +252,18 @@ unsigned char mmc_detect_card(mmc_card_d
argument = 0x00000000;
ocr_value = (0x1FF << 15);
- err = mmc_send_cmd(MMC_CMD0, argument, resp);
+ err = mmc_send_cmd(MMC_CMD0, argument, mmc_resp.resp);
if (err != 1)
return err;
argument = SD_CMD8_CHECK_PATTERN | SD_CMD8_2_7_3_6_V_RANGE;
- err = mmc_send_cmd(MMC_SDCMD8, argument, resp);
+ err = mmc_send_cmd(MMC_SDCMD8, argument, mmc_resp.resp);
hcs_val = (err == 1) ?
MMC_OCR_REG_HOST_CAPACITY_SUPPORT_SECTOR :
MMC_OCR_REG_HOST_CAPACITY_SUPPORT_BYTE;
argument = 0x0000 << 16;
- err = mmc_send_cmd(MMC_CMD55, argument, resp);
+ err = mmc_send_cmd(MMC_CMD55, argument, mmc_resp.resp);
if (err == 1) {
mmc_card_cur->card_type = SD_CARD;
ocr_value |= hcs_val;
@@ -272,24 +277,24 @@ unsigned char mmc_detect_card(mmc_card_d
}
argument = ocr_value;
- err = mmc_send_cmd(ret_cmd41, argument, resp);
+ err = mmc_send_cmd(ret_cmd41, argument, mmc_resp.resp);
if (err != 1)
return err;
- ocr_recvd = ((mmc_resp_r3 *) resp)->ocr;
+ ocr_recvd = mmc_resp.r3.ocr;
while (!(ocr_recvd & (0x1 << 31)) && (retry_cnt > 0)) {
retry_cnt--;
if (mmc_card_cur->card_type == SD_CARD) {
argument = 0x0000 << 16;
- err = mmc_send_cmd(MMC_CMD55, argument, resp);
+ err = mmc_send_cmd(MMC_CMD55, argument, mmc_resp.resp);
}
argument = ocr_value;
- err = mmc_send_cmd(ret_cmd41, argument, resp);
+ err = mmc_send_cmd(ret_cmd41, argument, mmc_resp.resp);
if (err != 1)
return err;
- ocr_recvd = ((mmc_resp_r3 *) resp)->ocr;
+ ocr_recvd = mmc_resp.r3.ocr;
}
if (!(ocr_recvd & (0x1 << 31)))
@@ -318,22 +323,22 @@ unsigned char mmc_detect_card(mmc_card_d
if (!(ocr_recvd & ocr_value))
return 0;
- err = mmc_send_cmd(MMC_CMD2, argument, resp);
+ err = mmc_send_cmd(MMC_CMD2, argument, mmc_resp.resp);
if (err != 1)
return err;
if (mmc_card_cur->card_type == MMC_CARD) {
argument = mmc_card_cur->RCA << 16;
- err = mmc_send_cmd(MMC_CMD3, argument, resp);
+ err = mmc_send_cmd(MMC_CMD3, argument, mmc_resp.resp);
if (err != 1)
return err;
} else {
argument = 0x00000000;
- err = mmc_send_cmd(MMC_SDCMD3, argument, resp);
+ err = mmc_send_cmd(MMC_SDCMD3, argument, mmc_resp.resp);
if (err != 1)
return err;
- mmc_card_cur->RCA = ((mmc_resp_r6 *) resp)->newpublishedrca;
+ mmc_card_cur->RCA = mmc_resp.r6.newpublishedrca;
}
writel(readl(&mmc_base->con) & ~OD, &mmc_base->con);
@@ -437,10 +442,12 @@ unsigned char configure_mmc(mmc_card_dat
{
unsigned char ret_val;
unsigned int argument;
- unsigned int resp[4];
unsigned int trans_clk, trans_fact, trans_unit, retries = 2;
- mmc_csd_reg_t Card_CSD;
unsigned char trans_speed;
+ union {
+ unsigned int resp[4];
+ mmc_csd_reg_t Card_CSD;
+ } mmc_resp;
ret_val = mmc_init_setup();
@@ -453,21 +460,16 @@ unsigned char configure_mmc(mmc_card_dat
} while ((retries > 0) && (ret_val != 1));
argument = mmc_card_cur->RCA << 16;
- ret_val = mmc_send_cmd(MMC_CMD9, argument, resp);
+ ret_val = mmc_send_cmd(MMC_CMD9, argument, mmc_resp.resp);
if (ret_val != 1)
return ret_val;
- ((unsigned int *) &Card_CSD)[3] = resp[3];
- ((unsigned int *) &Card_CSD)[2] = resp[2];
- ((unsigned int *) &Card_CSD)[1] = resp[1];
- ((unsigned int *) &Card_CSD)[0] = resp[0];
-
if (mmc_card_cur->card_type == MMC_CARD)
- mmc_card_cur->version = Card_CSD.spec_vers;
+ mmc_card_cur->version = mmc_resp.Card_CSD.spec_vers;
- trans_speed = Card_CSD.tran_speed;
+ trans_speed = mmc_resp.Card_CSD.tran_speed;
- ret_val = mmc_send_cmd(MMC_CMD4, MMC_DSR_DEFAULT << 16, resp);
+ ret_val = mmc_send_cmd(MMC_CMD4, MMC_DSR_DEFAULT << 16, mmc_resp.resp);
if (ret_val != 1)
return ret_val;
@@ -491,18 +493,18 @@ unsigned char configure_mmc(mmc_card_dat
return ret_val;
argument = mmc_card_cur->RCA << 16;
- ret_val = mmc_send_cmd(MMC_CMD7_SELECT, argument, resp);
+ ret_val = mmc_send_cmd(MMC_CMD7_SELECT, argument, mmc_resp.resp);
if (ret_val != 1)
return ret_val;
/* Configure the block length to 512 bytes */
argument = MMCSD_SECTOR_SIZE;
- ret_val = mmc_send_cmd(MMC_CMD16, argument, resp);
+ ret_val = mmc_send_cmd(MMC_CMD16, argument, mmc_resp.resp);
if (ret_val != 1)
return ret_val;
/* get the card size in sectors */
- ret_val = mmc_read_cardsize(mmc_card_cur, &Card_CSD);
+ ret_val = mmc_read_cardsize(mmc_card_cur, &mmc_resp.Card_CSD);
if (ret_val != 1)
return ret_val;
^ permalink raw reply [flat|nested] 4+ messages in thread
* [U-Boot] [PATCH v2] OMAP3 MMC: Fix warning dereferencing type-punned pointer
2009-09-25 18:30 [U-Boot] [PATCH v2] OMAP3 MMC: Fix warning dereferencing type-punned pointer Dirk Behme
@ 2009-09-25 20:08 ` Tom
2009-09-26 5:44 ` Dirk Behme
0 siblings, 1 reply; 4+ messages in thread
From: Tom @ 2009-09-25 20:08 UTC (permalink / raw)
To: u-boot
Dirk Behme wrote:
> Fix warning
>
> dereferencing type-punned pointer will break strict-aliasing rules
>
> Signed-off-by: Dirk Behme <dirk.behme@googlemail.com>
> CC: Steve Sakoman <sakoman@gmail.com>
>
This may be improved by consolidating the unions into the omap3 mmc.h file
and using a pointer to union in the mmc_send_cmd.
may == your choice
Ack-ed
Tom
^ permalink raw reply [flat|nested] 4+ messages in thread
* [U-Boot] [PATCH v2] OMAP3 MMC: Fix warning dereferencing type-punned pointer
2009-09-25 20:08 ` Tom
@ 2009-09-26 5:44 ` Dirk Behme
2009-09-26 12:29 ` Tom
0 siblings, 1 reply; 4+ messages in thread
From: Dirk Behme @ 2009-09-26 5:44 UTC (permalink / raw)
To: u-boot
Tom wrote:
> Dirk Behme wrote:
>> Fix warning
>>
>> dereferencing type-punned pointer will break strict-aliasing rules
>>
>> Signed-off-by: Dirk Behme <dirk.behme@googlemail.com>
>> CC: Steve Sakoman <sakoman@gmail.com>
>>
>
> This may be improved by consolidating the unions into the omap3 mmc.h file
> and using a pointer to union in the mmc_send_cmd.
Hmmh, I'm not so familiar with unions ;) But moving
union {
unsigned int resp[4];
mmc_resp_r3 r3;
mmc_resp_r6 r6;
} mmc_resp;
and
union {
unsigned int resp[4];
mmc_csd_reg_t Card_CSD;
} mmc_resp;
into the omap3 mmc.h would mean to make them global and to permanently
allocate the space for resp[4]? That is, make local variables
allocated locally (on stack?) move to global variables using
(wasting?) some additional memory? If so, I'd like to keep stuff local
as done by the original version. Sorry if I missed something ;)
Best regards
Dirk
^ permalink raw reply [flat|nested] 4+ messages in thread
* [U-Boot] [PATCH v2] OMAP3 MMC: Fix warning dereferencing type-punned pointer
2009-09-26 5:44 ` Dirk Behme
@ 2009-09-26 12:29 ` Tom
0 siblings, 0 replies; 4+ messages in thread
From: Tom @ 2009-09-26 12:29 UTC (permalink / raw)
To: u-boot
Dirk Behme wrote:
> Tom wrote:
>> Dirk Behme wrote:
>>> Fix warning
>>>
>>> dereferencing type-punned pointer will break strict-aliasing rules
>>>
>>> Signed-off-by: Dirk Behme <dirk.behme@googlemail.com>
>>> CC: Steve Sakoman <sakoman@gmail.com>
>>>
>>
>> This may be improved by consolidating the unions into the omap3 mmc.h
>> file
>> and using a pointer to union in the mmc_send_cmd.
>
> Hmmh, I'm not so familiar with unions ;) But moving
>
> union {
> unsigned int resp[4];
> mmc_resp_r3 r3;
> mmc_resp_r6 r6;
> } mmc_resp;
>
> and
>
> union {
> unsigned int resp[4];
> mmc_csd_reg_t Card_CSD;
> } mmc_resp;
>
> into the omap3 mmc.h would mean to make them global and to permanently
> allocate the space for resp[4]? That is, make local variables allocated
> locally (on stack?) move to global variables using (wasting?) some
> additional memory? If so, I'd like to keep stuff local as done by the
> original version. Sorry if I missed something ;)
>
I ment just the declaration like
union mmc_resp_t {
unsigned int resp[4];
mmc_resp_r3 r3;
mmc_resp_r6 r6;
mmc_csd_reg_t Card_CSD;
};
variables would still be defined in the C file.
Tom
> Best regards
>
> Dirk
>
^ permalink raw reply [flat|nested] 4+ messages in thread
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2009-09-25 18:30 [U-Boot] [PATCH v2] OMAP3 MMC: Fix warning dereferencing type-punned pointer Dirk Behme
2009-09-25 20:08 ` Tom
2009-09-26 5:44 ` Dirk Behme
2009-09-26 12:29 ` Tom
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